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Full text of "Sinclair User Magazine Issue 004"

July 1982 



The independent magazine for the independent user 



LEARNING IS FUN 
WITH THE ZX-8J 



We look inside 
Spectrum 



V 



V 



I 



/ 



I 




r 



Tuning-in 
to ama" 



Our next great 
competition 





ZX81 B.B.C. MICRO ATOM VIC 




A MAZE ADVENTURE 
GAME FOR 

indaii- ZX8I 



<*r**~ 





100 The Albany, Ofd Hall Street, Liverpool L3 9EP 



ZXA5 ASSEMBLER 
ZXDB DEBUGGER 

ZXTK TOOLKIT 

MULTIFILE 

MAZOGS_ 



IHlLHjO is a brand new game for the 16K ZXS1, 
unlike any other game you've seen on the ZX81. This is 
without doubt the best game available ior this computer, 
and ii you donf believe us, ask somebody who has 
seen it, or go down to your local computer shop and 
ask for a demonstration. 

MAZOGS is a maze adventure game with very fast- 
moving animated graphics. A large proportion of the 
program is written in machine code to achieve the most 
amazing graphics you have ever seen on the ZX81. 
You will be confronted: by a laige and complex Maze, 
which contains somewhere within it a glittering and 
fabulous Treasure. You not only have the problem of 
finding the treasure and bringing it out of the maze, you 
must also face the guardians of the maze in the form of 
a force of fearful Mazogs. Even if you survive their 
attacks you could still starve to death if you get 
hopelessly lost. Fortunately,, there are various ways in 
which you can get help on this dangerous mission 
There are three levels of difficulty and the game comes 
complete with comprehensive instructions. The cassette 
on which the game is supplied is of the highest quality, 
and loading is guaranteed. 

Mazogs is available from Bug-Byte and most good 
computer shops at £10. inclusive 




£5.00 DICTATOR E9 00 

-£6.50 DAMSEL A THE BEAST_ EG 50 

.£6.00 CONSTELLATION £8.00 

£17.50 PROGRAM PACKS 

£10.00 1-8 (each) _ f * nn 



VICMEN E7 .00 

ANOTHER VIC IN THE WALL £7.00 



VIC GAMMON. 
ASTEROIDS _ 



£7 00 
£7.00 




'-'"frfi 



OOB Micnoijk 



SPACE WAHP 

BBC CHESS 

BBC MULTIFILE. 



BBC BACKGAMMON. 
BBC GOLF 



£11.50 

£11.50 

£25.00 

£8 00 

_£7D0 



ATOM 




X 




INVADERS 
CHESS _ 



747 FLIGHT 
SIMULATION . 
GAUUOANS _ 
BREAKOTJT_ 



£8 00 
£9.00 

CS.0Q 
£8,00 

£4.00 



FRUIT MACHINE 
PTNBALL 



LABYRINTH 

LUNAR LANDER 
GOLF 



£400 
£4 50 

£7 00 
£5,50 

. £5,00 



ALL PRICES INCLUDE POSTAGE 



I 




Expiry date 



Please send urn 

I enclose ch*gu*/PQ. ior 

OB Pleas* dsbil my: Access 5224 

Bardaycrard 4329 

Name 

Address 

Cod* .... 
Dealers Difci^HinJ Available 

ACCESS, BAKCLAYCARD ORDERS WELCOME ON 34hi 
ANSAFHONE 06L-227 2643 or mail to 
BUG-BYTE SOFTWARE, 
FREEPOST,{No stamp req.) 
LIVERPOOL L3 3AB. 



I 
I 




ZX8I B.B.C. MICRO ...-.ATOM VIC 



contents 




Consultant editor 

Mike Johnston 

Production editor 

Haraki Mayes 

Design 

William Scalding 

Advertisement director 
Simon Horgan 

Editorial director 

fohnSterticchi 

Advertisement manager 
Lea Morton 

Editorial production assistant 
Margaret Hawkins 

Managing director 

Terry Cartwright 

Chairman 
Richard Hease 

Sinclair User is published monthly 
by £CC Publications Ltd. It is not in 
anyway connected with Sinclair 
Research Ltd. 

Telephone 

MJ departments 

01-359 74B1 

If you would like to contribute to 

Sinclair User, please send typed (or 
beautifully-handwritten] articles or 
prog rams 10: 
Sinclair LI ser 
ECC Publications. 
30-31 Islington Green. 
Loodoo.Nl SB| 

Wo will pay £10 for each program 
printed and £50 for each article, 
which should be approximately 
1.000 words long. 

Copyright 1982 
Sinclair User 
ISSN No. 0262-5458 
Origination at 
Outline Graphics. 
Printed by 
Eden Fiaher (Southend) Ltd 

Distributed by 

Spotlight Magazine Distribution Lid, 

I BenwelJ Road, 

Holloway, 

London N7 

01-607 0411 



page 6 parse 14 

5 SINCLAIRVQYANCE Wo consider the future for retailing in the Sinclair market and 

its effect on suppliers. 

6 SCHOOLS SPOT A teacher, Dave Stiyera. writes about his experiences using the 
ZX-91 in hie school. 

9 LETTERS More brickbats and bouquets from our readers 

10 SINCLAIR USER CLUB As our special club (fats under way, we offer our second 
Star Bargain to dub members. 

14 SPECTRUM REVIEW Stephens Adams looks inside the new Sinclair machine and 
likfis what he sees. 

19 NEWS W H Smith's future plana, ZX shows around the country, and the 
sponsorship of Uie Cambridge half-marathon. 

22 AMATEUR RADIO Julian Moss looks al the uses of the ZX-fll in radio shacks, 

25 NtW USERS Last month, Nicole Segre told the story of the mother's lament oHior 
I sons new computer. This month she tells how she fought back. 

| 28 READER SURVEY We ask you to tell us what you think of Sindair User and the 
| market for Sinclair products and spin-offs 

31 PROGRAM PRINTOUT Another eight pages of special programs, with one for the 
IZX-80, 

4 1 PROGRAM AIDS Phil Garrett looks at disa assemblers and assemblers which are 

| on the market. 

45 SOFTWARE SCENE We look at the new programs. 

47 HARDWARE WORLD More or the now items in die hardware market arm 

I review ad. 

52 NEW BUSINESS Richard Altwa&Bor end Steven Vickers, two of the loading figures 
| in the design of the Spectrum, have launched their own company. 

56 HELPLINE Andrew Hewson and more of the problems which people find in using 
| their Sinclair machines. 

59 MIND GAMES Philip loy examines a game of chess which can fit into 1 K. 

62 MACHINE CODE The final part of the series by Mike BiddeU on machine code 

programming. 

64 COMPETITION Following the success of our previous competitions, we offer 
another printer and the Memopak 64K RAM pack as prizes this month. . 

65 ADVERTISEMENT INDEX Your guide to the many items on offer in the pages of 
SincJuif User. 



NEXT MONTH 

• We assess Sinclair's new range of 
educational software 

• More of your queries answered in 
Helpline 

• ANOTHER GREAT OFFER TO SINCLAIR 
CLUB MEMBERS 



SINCLAIR U SEH July 2982 



ZX-81 




FIRST CH0IC3E FOR ZX: SUPPORT: 



ZX-80 




QS DirEKDER. 
UP -DOWTI THRUST -FIRE 
First and only full screen display. 
Software to drive QS SOUND BD. 
Moving Flanetaiy surface. Up to 
84 fast moving characters on 
screen at once. On screen scoring. 
Ten missiles at once, Increasing 
attack patterns Requires 8K 
ROM, and 4K mln Of RAM. AS. BO. 

QS SOUWD BD. 

A programmable sound effects 
board using the AY-3-8910. 3 
TONES; 1 NOISE i ENVELOPE 
SHAPER: + TWO 8 BIT I/O PORTS. 
Easily programmable from 
BASIC, the AY chip does most of 
the work leaving your computer 
free for other things. Signal O/F 
via 3.5 mm Jack socket Ports 0/P 
via a 16 pm I-C. Socket 486,00. 

QS CHRS BD./ 

A programmable character 
generator giving - 128 SEP- 
ARATELY PROGRAMMABLE 
CHARACTERS ON/OFF SWITCH, 
IK ON BOARD RAM. Enables 
creation and display of your owm 
characters to screen or printer. 
Demo cassette of fast machine 
code operation routines and lower 
case alphabet included- See below 
for ZX PRINTER listing. AZ6.O0. 




QS IWVADBBB. 

LEFT RIGHT - FIRE 

13X7 INVADERS; High score; 3 

levels of play; RND saucers; Bonus 

base Drives Soi l ndbd fif CHRS bd . 

Requires 7K RAM, 8K ROM + Slow 

AB.BO, 




.OuER 



CASE 



i t C <i t f 9 h I j k l(lO0Pflf|tui/ii)(<i( 



QS HI-RES BD. 

A Hi -res graphics board giving 
236 * 193 PIXELS 6K ON RD. 
RAM, SOFTWARE SELECT/ 
DESELECT. MIXED TEXT AND 
GRAPHICS. 2K ON BOARD ROM 
Resident fast machine code 
graphics software ( in ROM ) 
provides the following HI -RES 
Commands- MOVE x,y; PLOTx, 
y; DRAW x, y ; BOX x, y ; UP; DOWN ; 
LEFT; RIGHT; PRINT A*; SCROLL: 
BLACK; WHITE CLEAR COPY See 
above for ZX PRINTER listings 
using COPY 4-SB.OO, 




Q8 ASTEROIDS 

LEFT -RIGHT THRUST FIRE 
Si .ftwara to drive QS SOUND BD. 
Multiple missiles firing In 8 
directions. On screen scoring. 
Increasing number of asteroids 
Full mobility of ship to all areas of 
the screen. Two asteroid sizes. 
Bonus ship at 10,000 points. 
Requires 8K ROM, 4K mm of RAM 
+ SLOW function. AS. 80, 

QS 3K RAJA Bd. 

An extremely reliable static RAM 
Bd. which combines with the 
computer's memory to give 4K 
total, Plugs direct in to the rear 
port on your ZX Computer. 
A1B.00. 

QS MOT HER BOARD BD. fr QS 
CONNECTOR 

A reliable expansion system 
allowing a total of any RAM p&Cfe 
plus two other plug in boards to be 
in use at once On board 5V 
regulator drives all external 
boards. Fitted with two 23 way 
double sided edge connectors. 
Connector IS 2 * 23 way edge 
conns soldered back to back. 
Expansion can operate in two 
ways - (1 ) COMPUTER- - 
CONNECTOR * - Any QS add on bd. 
( but no extra RAM pack I (2) 
COMPUTER- -CONNECTOR*-* 
MOTHER BD ■ ■ ANY RAM PACK. 
r 2 bds to fit in mother bd > Mother 
board Al&.OO Connector A4.0O, 



Special offers & news 



C 1 3 <JB PIUKTTE W"ACE Connects a. ZX Printer to an. Acorn Atom. Simple. 

frasy to use, gives listings, commands and Hi-Res screen dump. On beard 

BE ROM JL8B.0O 

(3] QBHAJ&MOHIT A machine cods programme for the QS sound board. 

gives you easy control of phasing,, chorus, tempo, volume, pitch. Complete 

with sample pro-gramme to play the serenade from Mozart's Don Giovanni 

ZXS1, 4KRAM *4.DO 

<3> QS Mother bd. + connector '•-CHRS bd + Tne special Graphics version of 

ARCTIC COl U ' U T B f&'g ZX CHESS 11. A.40.00. 

The strongest chess program with 7 levels of play. 



POSTAL AND MONEY ORDERS TO: ALL PRODUCTS FULLY GUARAKTTED. 

QUIGKSILVA: 9S, UPPER BR0W1VHILL BJ>. : MATBTJSH : SOTOH : HANTS : MWQImAWD. 

Please state Type of machine. Which ROM. Memoi^y size, when ordering. 




sinclairvoyance 




Tempting gap in market 

TF ANYONE questioned the size of the possible and are unlikely to be in the future. That is 
_i _* j^_ u „. — ^„ t ^i. ihov ahnnlH tnkft eaoeciallv true of the home computer market, 



and are unlikely to be in the future, 
especially true of the home computer 
where changes can happen so quickly. 

The British companies involved are also small. 
One big push by a large Japanese conglomerate 
could be sufficient to push them on to the sidelines. 
If the market is as big as estimated, it would not 

a particularly 




IF ANYONE questioned the size of the possible 
market for home computers, they should take 
note of the experience of W H Smith. The 
company sells more magazines on computers than it 
does women's magazines. There are three 
computer publications which sell more copies than 
the most popular women's magazine. 

ThiB explains why Smiths is expanding that side even be necessary to launch 
ofitsretailingsteadily.Asthecompanyputsit.most innovative product model 

of its sales are in "maturing markets" , so the need It would be pleasant to think it would be a Bntish 
to find new and dynamic lines is essential for its company which takes the pli 

future. 

The growth potential is phenomenal It is 
estimated that, despite sales of almost 500,000 
ZX-61s, Sinclair Research has tapped only about 
two percent of the estimated home computer 
market. Despite allowing for the fact that it is 
difficult to assess a market which did not exist two 
years ago, there is still an enormous hole in the 
market. 

Smith's reaction in the medium term is to try to 
cover the whole market for both hardware and 
software. In the long term, it is thinking of 
specialising on one sector, probably software. That 
ensures that the route future development will 
follow is much the same as that for the music 
market — few people these days expect to be able to 

buv records in the same place as they buy their especially, to put new ideas into practice quickly, 
music systems rhG freedom, however, is not total. In the end it is 

Follow the route a little further and you begin Clive Sinclair who takes the important decisions. 

Having tasted some easing of constraints, it can be 
very frustrating when there is still some Limitation 

to action. 

It was that frustration which led to the departure 



THERE IS possibly something to be said for the 
ponderous decision structures of many of Britain's 
major companies. With the limitation of personal 
initiative and the promotion of company spirit, the 
wish to leave and start a new business is severely 

curtailed. 

Compare that to Clive Sinclair's companies, past 
and present, where initiative and freedom of 
thought have been encouraged. It is one of the 
benefits of being a small company that it is possible 
and it has been used, by Sinclair Research 



talking about computer systems designed for home 

use. One vision of the futuie, suggested by W H 

Smith, is that people start by buying some kind of 

simple keyboard which, in basic form, could be used 

as a typewriter or calculator. To this could be of Richard Altwasser to >oin a growing band of 

added various types of processor, memory and former Sinclair colleagues from whom he now 

orinter to build a personal system to suit a variety faces some form of competition. 

of requirements The P e °P le behind Acorn Computers and the 

Such thinking is perfectly logical and likely to Grundy Newbrain, which finally was launched last 

happen since it sounds very like the way in which month, all worked with Sinclair at some stage. 

Sony developed the music market. Before Sony split Altwasser and his partner, Steven Vickers are 

music centres into various parts, most people keeping quiet about their plans but it is unlikely hey 

listened to their music on record players built as will be straying far from the microcomputer field 

one unit. Such a thought prompts the question as to they know so well, 

what the Japanese are doing about the home Whether their new company will be bjg enough to 

computer market consider launching a new computer is open to 

It would be comforting to think that the lead conjecture. Leaving that aside for the moment 

which Sinclair Research and other British there is still a large market in software and 

companies have in the field would be an advantage hardware peripherals where they could compete 

but such leads have been no insurance in the past with their former employer. 



SINCLAIR U SER July 1 962 






Simplicity is best 
learning pattern 

Dave Sayers relates how the ZX-81 has 
helped learning in his school. 



THE POWER of a micro as a 
learning tool is often Quoted 
in papers and magazines, yet 
most of the published programs are 
games and adventures — and good 
they are, too* Nonetheless, it is a pity 
that more educational games are 
not published; the little ZX-81 with 
even a basic IK memory can be used 
to teach many of the fundamentals 
of mathematics or, with more 
memory, English. 

The example programs included 
in this article, therefore, are all 
written within IK. The reason is 
simple. To be good, a teaching game 
need not be complicated. Preferably 
it should teach only one thing, 
though that is not to say that 
mixtures of approaches are not 
desirable. 

It should also* if possible, have a 
graphics display to help keep the 
attention of the child. Another good 
reason for keeping games simple is 
that many ZX owners, or owners of 
other machines, are young people 



used to help to teach children who 
can count who have difficulty in 
associating those numbers with the 
written number — for instance, 
seven. 

As you can see, 1 am starting at 
the very first basis of counting. My 
daughter has started learning to 
write, or record, numbers greater 
than 10, and this kind of game can be 
a great help. A program I have used 
flashes rows of squares for her to 
input the number — figure two. It 
was written specifically to help her 
understand the way in which 
numbers above 10 are recorded. 
The same program, of course, can 
be adapted easily to give help with 
numbers above 20. 

Although the programs may 
appear limited, they are still giving 
valuable practice in learning skills 
which, if not understood fully, can 
lead later to difficulty in 
comprehending, for instance, the 
value attached to a carried l — in 
9 + 9 we "carry one" which is really 




'The little ZX-81 with even a basic IK 
memory can be used to teach the funda- 
mentals of mathematics mathe matics' 



like myself who have children at 
school. With the ZX available, it 
would be a waste if it ware not used 
constructively to further a child's 
education. 

Initially most people probably 
write programs of the 6x5 = ? 
variety. They are useful but not 
especially interesting. Try the 
program in figure one. 

It is very simple; the program 
prints out 10 rows of graphics 
squares, with the number of 
squares printed at the end. It can be 



10. You may say that is well known 
but rest assured there are plenty of 
children who find the true value of a 
carried figure a total mystery. 

Computer-aided learning can give 
those children valuable lessons, for 
they will know immediately if they 
are correct or incorrect. In classes 
where books are marked once a 
lesson, the incorrectness of what 
they have done may become 
apparent only at the end of the 
lesson — or next day. 

Once we have the child under- 



standing counting to a certain total, 
speed practice becomes important 
in helping the child to rely less on 
physical cues of number and begins 
to depend on their internal memory 
of where they are in the count. The 
games should show varying 
numbers of shapes quickly on the 
screen, for which a running total 
has to be kept by the child, to be 
entered at the end of the run. 

HISSING SID is an example of 
such a program. Snakes appear on 
the screen, varying numbers each 
time. A total is input at the and, 
which is checked — figure three. 

There is plenty of fun while 
learning to count with this program, 
especially if it is altered to print the 
total at the end, after a short pause, 
to give children a chance to shout 
the answers. They love to see who 
can be first with thecorrect answer. 
Figure four shows how to do this. 

This program can be altered in 
both spaed of display and numbers 
of snakes. For larger numbers alter 
line 20 and for less time between 
displays alter line 100, If you make it 
long enough and quick enough it 
becomes fairly testing, even for 
adults, 

I wrote a similar program on the 
Pet at school arid tried it on my own 
class, as well as the class of a 
colleague. 

My class, by now fairly blase 
where micros are concerned — 
same of them prefer me to use theZX 
their fathers or brothers own one 
and they can crib my programs — 
enjoyed it a great deal. The 
colleague, who was interested in 



SINCLAIR USER July 1982 




school 



what the computer could do, was 
surprised by the way in which some 
of the less-motivated children were 
captivated by the game. She was 
particularly impressed with the 
way in which one boy, who was 
finding addition a trial, began to 
store the numbers in his head; then, 
staring into space for a minute or so, 
as he totalled them, he finally 
delivered his answer in a very 
positive way, 
Gone were the uncertainties he 



had about written sums, when he 
would often he at the teacher's desk 
complaining that he could not 
understand. Replacing it was the 
desire to beat the computer, to have 
his answer before it flashed on the 
screen* 

BRIDGES is a game in which the 
children attempt to build a bridge by 
answering addition questions 
correctly. Each correal answer puts 
another span on the bridge, As 
before, they are adding blocks. 



rether than numbers — figure five. 

When the game is run, blocks, in 
two rows, appear on the screen. If 
they are added correctly, a span is 
added to the bridge. If they are not 
added correctly, there is no penalty; 
the problem resumes again and 
again until it is solved correctly. 

That is important, as there is no 
worry that the child will feel he or 
she has failed on the first few 
attempts if the bridge is not nearing 
completion. 

Those with IB or more K of 
memory might like to improve this 
program. For instance, the bridge 
may fill the whole screen and every 
time there is an incorrect answer a 
man might walk along the bridge 
and fall off, to land in a boat, from 
where he is returned to the bridge to 
climb and try again. Whether you 
use these ideas or not. it is important 
to pay careful attention to what you 
want your program to teach and 
never to take for granted the idea 
that children understand the logic 
of mathematics. 



1 Figure 1- 




170- 


FOR 1-1 TO 100 


10 


FOR I«l TO 10 


180 


NEXT I 


.-'i-V 


FOR <J=1 TO T 


130 


GOTO 5 


30 


PRINT "M "; 






4-0 


NEXT J 


Figure 4 . 




5© 


PRINT T 






60 


PRINT 


Change these lines 


70 


NEXT I 


130 for 


U= 1 lo 150 


npmi. 




140 next u 


IB 


LET fl=HNT *RMI>#110.1 + H2I> 






sa 


CL;. 






30 


FOR 1=1 TO fl 


Do not f 


40 


PRINT r "™ "; 






50 


NEXT I 






^5 


PRINT 


Figure 5 




60 


INPUT B 


1 


LET S=© 


7« 


IF fl=B THEN GOTO lO 


5 


PR INT 


80 


PRINT "URONP IT UFI& ', Pi 


6 


PRINT 


90 


FOR 1=1 TO 100 


T 


PR INT 


100 


NEXT I 


10 


FOR 1=1 TO 10 


110 
120 


CLS 
GOTO 10 


20 

3 


PRINT "Mifl0 SPRCESJ^i" 


Figure 3, 




40 


LET R=(INT (RND*9) +1J 


5 


CLS 


50 


LET e=(lNT (RND*9) f-1) 


10 


let c=a 


60 


FOR 1=1 TO R 


£0 


LET ft= 1 INT CRND*5J +1? 


70 


PRINT RT 15^X; ,, |" 


30 


FOR 1=1 TO R 


O0 


NEXT I 


4-0 


LET B=(INT (RNDS6J +1J 


90 


FOR 1=1 TO E 


50 


let c=o+e 


100 


PRINT RT 17 j I; '■ |" 


60 


FOR J = l TO B 


110 


NEXT I 


70 


PRINT " (3 SPACES) -HBWflrtrtrtfA 


120 


LET 3=S+1 


VASV 


130 


INPUT D 


30 


PRINT 


135 


IF D-f>P,+B THEN LET 5=5-1 


■30 


NEXT J 


140 


IF D=fl+S THEN PRINT RT 3,3+ 


100 


FOR K=l TO 70 


■ . . i ^H . 

J. J 




110 


NEXT K 


150 


IF S=10 THEN GOTO 300 


US 


OLS 


160 


PRINT RT 15,l; ,h <12 SPP.CE*)" 


120 


NEXT X 


173 


PRINT RT 17,1, "(12 SPACES) " 


130 


PRINT "HOU MANY &NRKE5?" 


160 


IF 5 = 10 RND D=R+B THEN GOTO 


140 


INPUT D 


400 




150 


IF 0=C THEN GOTO 5 


190 


IF D=fl+B THEN GOTO 40 


16© 


PRINT "THERE WERE "<;C;" SNA 


£00 


GOTO 60 


KES" 




400 


PRINT "YOU BUILT R BRIDGE" 



SENCLAIEUSEH JjJy19fl2 



Explore the Excellence 

^ofyourZX81 

■ML V nii«h mcmATCm AHH-Anc 




Unique 
Smooth 
trade-in offer! 

For your future needs, we'll 

allow you £10 against your 
purchase of out 64K model if. 

you return your 1 6K pack within 3 
months of receipt: 

you supply evidence of purchase: 

your 16K model is received by us 
undamaged and unopened." 

" W* WSfl/vp the ngbt to reySCf. tor discounting puipOS*S. ufM& 
mtt&\ nave been either oj»rt*f? of damaged in any way 



ntnoTECH 

ADD-on 



UBT 




mm mcmorecn add-ons 

Hi^h Resolution Graphics 

Fully programmable- high 

resolution (192*248 

pixels). 

Video page is both memory 

and bitmapped. 

Video page can be located 

anywhere in the RAM. 

The number ol video pages 

15 limited only by your RAM 

size (each page occupies 
about 6-5K RAM) and 

pages can overlap 

• Instant inverse video. 
Switching inverse video on and 
off gives flashing characters/numerals etc 
Video pages can be • Access to video page is 
superimposed by similar lo plot and unploi 

sof iwa r e switching com mands in S AS! C . 

The pack comes in an elegant aluminium case, anodssed black and 
styled to fit onto the backoMhe ZXBt. allowing more add-ons (Memopak 
RAM". Sinclair printer, etc} 10 be connected without a further power supply. 
It contains a 2K EPRQM monitor, holding a full range of graphics subroutines which 
can be called by ihe BASIC USR function or by machine code. 

Memopak 1BK Memory Extension 

It is a fact that the ZX81 has revolutionised home computing and coupled wilh the new 
Memopak 16K it gives you a massive 16Kof Directly Addressable RAM, which is neither 
switched nor paged. Wrth Ihe addition of the Memopak 1 6K your ZX81 s enlarged 
memory capacity will enable it to execute longer and more sophisticated programs, and to 
hold an extended database 

The 1 6K and 64K Memopaks come in attractive custom-designed and engineered cases 
which fit snugly on to Ihe back of the ZX81 giving firm, wobble-free connections. 



fwroorccn 

flOD-Ofl 



UBT 




Memopak 64K Memory Extension 

The 64K Memopak is a pack which extends the memory of the ZXB1 by a further 56K, and 

together wilh Ihe ZXSi gives a full 64K, which is neither switched nor paged, and is 

directly addressable. The unit is user transparent and accepis BASIC commands such as 

10DIMA(9000). 

BREAKDOWN OF MEMORY AREAS 

0-BK Sinclair ROM S-1 6K . This section ol memory switches m or out m 4K bfocks 

to leave space lor memory mapping, holds its contents during cassette loads, allows 

communication between programmes, and can be used lo run assembly language 

routines 16-32K . , This area can be used for BASIC programmes and assembly 

language routines. 32-64K . . . 32K of RAM memory lor BASIC variables and large arrays. 

Wilh the Memopak 64K extension the ZX81 is transformed into a powerful computer. 

suitable for business, leisure and educational use, at a fraction ol the cost of comparable 

systems. 



Coming Soon... 



MEMOPAK RAM i 
m-HES GRAPHICS 
CENTRONICS! 




f Please make 
cheques payable to 
MEMOTECH Ltd. 



Please send me 



Price No 



Total 



Please Debit my 

I Access/ Barclay card' 



1SK RAM (ft £26 00 + £3 90 VAT 



64K RAM (it £68.. 69 ~ £10.31 VAT 



HRG (ft £52 00 + £7 80 VAT 



E29 : +" 



£79.00 



£59 80 



account number 1 Packaging & Postage («■ £2.00 per unit 




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.DATE . 



A complete range of ZX81 plug-m penpherals 
Centronics Interface & Software Drivers 
Digitising Tablet RS232 Interface 

We regret we are as yet unable to accept 

orders or enquiries concerning the above 
products, but we'd lei you know as soon 
as they become available 

© R. Bttnlan & G.A.C. Boyd 1 9C2 *— — . — - — — — ^— — — — — — ^— ^— — — 

We want to be sure you are satisfied with your Memopak - so we offer a 14-day money back Guarantee on all our products, 
Memotech Limited, 3 Collins Street, Oxford 0X4 1XL, England Tel: Oxford (0865) 722102 Telex: 837220 Orchid G 



. ADDflESS. 



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-I 




letters 



Memory 
wobbles 



MUCH h as been w r i t ten on 
the subject of RAM pack 
wobble. little of it giving 
any sound advice as to how 
it may be prevented. I feel 
that the three solutions 
which I have found are the 
best to date. 

The Sinclair RAM would 
be as good as any other, 
except for the fact that it 
does not appear to be very 
eager to stay on the 
computer and will jump off 
when any key is touched 
hard enough. 

If you have E2 to spare, 
you can buy a ribbon cable 
and solder one end to the 
RAM and plug the other to 
the edge connector of the 
PCB. That means that 
when you hit a key too 
hard, all that happens is 
that the ribbon cable 
absorbs the shock. 

The second method is 
simpler and cheaper and 
just as effective, All that 
you do is to take a piece of 
Blutack and place it on the 
RAM, above the edge 
connector. When you plug 
in the RAM it is held to the 
computer by the Blutack. 

The third way to stop 
RAM wobble, however, 
does not concern the 
Sinclair RAM but the Byg 
Byte RAM, Initially there 
is nothing wrong with the 
RAM and it is a very good 
alternative to the Sinclair 
RAM but the case is about 
three times the size it 



should be and so it pulls 
the connections apart. The 
answer is simple — just 
remove the case. 

Giles Colborne, 

Galampton, 

Devon. 

Stopping 
whiteouts 

I WAS very interested in 
your article on the ZX-fll 
16K RAM pack, in part- 
icular the part which 
stated that the computer 
can suffer from whiteouts 
due to the fluctuations in 
the mains supply. 

I have found that to be 
an annoying problem, 
especially when loading a 
program which takes more 
than four minutes to run. 

I have heard that is due 
to the voltage spikes in the 
grid over-loading the 
memory and re-setting it to 
the input mode, leaving the 
mode K on my screen, 
which has happened to me. 

I know that this is the 
problem, as the same tape 
and equipment will record 
perfectly during the times 
when the grid system is not 
being used a great deal: 
i.e., before 8,30 am and 
between 2 pm and 4 .30 pm. 
It is not always convenient 
or possible to work on my 
computer at those times; 
mostly I like to work in the 
evenings, which can be the 
worst time for the pro- 
blem. 



I know that you can ob- 
tain a filter unit which 
goes between the wall 
socket and the computer 
plug which will suppress 
the spikes but I do not 
know which type would be 
best for myZX-81. 

Could you advise me as 
to which method of solving 
the problem you would 
suggest and where the 
goods can be obtained? 

Paul Coker, 
London SMB. 
•Can readers help? We 
are sending it to out 
Helpline correspondent, 
Andrew Hewson, to see if 
he knows the answer. 

Apple threat 

I AM very grateful for the 
April issue of Sinclair User 
but it does not tell me how 
to make my printer work. 
The books which are sold 
do not tell you, either. It 
would be much better if 
you told people how a 
ZX-61 works, otherwise I 
shall have to sell mine and 
buy an Apple. 

I write and write again 
to Sinclair, without even 
an acknowledgment, 

Maurice Nadin, 
Surrey. 
•We hope fate? issues 
have been more help and 
that you have not been 
compelled to take the 
drastic step of buying an 
Apple. 

Changing to 
machine code 

CONGRATULATIONS on 
an excellent magazine. It 
is just what ZX users 
wanted. I am not a pro- 
grammer and prior to buy- 



ing my ZX I did not have a 
clue. Through practice, I 
am rapidly picking-up the 
techniques and find the 
hobby very interesting. I 
find, having bought some 
programs written in 
machine code, that they 
are eminently superior to 
anything I have written, or 
purchased, written in 
Basic. To you, that may be 
an obvious statement but it 
has become clear to me 
only on running them. 

What I would like to do 
is to understand machine 
code — of which I now 
understand the basic prin- 
ciples — and. if possible, 
to buy a program which 
could convert some of my 
many Basic programs into 
machine code. Is that 
possible? 

From your advertise- 
ments there are one or two 
firms offering products 
which look as if they may 
answer the problem — 
Control Technology. Bug 
Byte, to name two — but 
they do not give sufficient 
detail for me to decide, 

I am told that what I am 
really looking for is a Com- 
piler but I have not yet 
seen anything advertised 
as such. Does one exist? 
Can you recommend any 
good books or a contact 
with whom to discuss the 
matter? 

D K Wall, 
Manchester. 
• Do readers have any a.d- 
vice? Meanwhile, we have 
passed the query to 
Andrew Hewson, our 
Helpline correspondent. 

•Letters should be kept as 
brief as possible and ad- 
dressed to The Editor, 
Sine/air User, 30-31 Isl- 
ington Green, London 
NlBBJ. Space considera- 
tions mean that it may be 
necessary to edit long let- 
ters, 



SINCLAIR USER ftiiy 1982 









AS A FURTHER service to users of Sinclair computers, Sinclair 

User is starting the Sinclair User Club. 

Membership will cost £12, which will enable members to 

enjoy a large number of extra benefits. They will include a 

bi-monthly cassette-based newsletter containing programs 

and answering problems, and many special discounts on a 

variety of goods of interest to ZX owners. 
Sinclair User will also contain stories about the club and its 

activities in each issue. 

It is intended to build-up the number of items which will be 

available at special prices to club members, with a Star Offer 

each month. 

Readers wishing to share the benefits of membership of the 

Sinclair User Club should complete the form below. 

I'memb^rsIIipTorm ! 

1 I wish to join the Sinclair User Club and enclose my subscription of £12 

Name j 

Address 

I ■ •-. ' j 

Send your coupons to Sinclair User Club, ECC Publications, 30-31 

I Islington Green, London Nl 8BJ. Cheques should be made payable to | 

I Sinclair User Club. 

i — , . ■ ■ — 

10 SINCLAIR USER luly19BZ 



Sinclair user 
club 




£3 off the Dean 

Electronics 

keyboard 




For this month's bargain, open only to members of the Sinclair User Club, we 
are offering to reduce the price of what many people consider to be the best 

keyboard available for the ZX-81, the Dean Electronics keyboard. 
It is simple to fit, plugging straight into the ZX-81 after the built-in keyboard 
has been unplugged. It has 47 keys, six more than the ZX-81. The extra keys 

can be used for whatever the owner wishes. 
The normal price is £35 but we are able to offer the keyboard through Buffer 
Micro Shop for only £32. In addition, the case, which usually costs £14.50, is 

offered at £13.50. 
Membership cards must be shown or numbers must be quoted when taking 

advantage of the offer, which closes on July 31. 
Buffer Micro Shop is at 3 74 A Streatham High Road, London SW16, next to 

Streatham Station. 



Each month Sinclair User will be listing, free, the growing 

number of ZX user groups throughout the world. 

We hope the list will be comprehensive and if anyone is 

forming a new group or knows of one we have not included, 

please let us know. 



Britain 

Aylesbury ZX Computer Club; Ken Knight. 22 Muunt St rant 

Aylesbury (5181 or 630867), Mealing: first Wednesday and Ihird 

Thursday uf the munth. 

Edinburgh ZX Users' Club; J. Palmer (031 681 31 as) or K Mi In hoi I 

(031 334 8483). Meetings: second Wednesday of the month at 

ClaremutH Hotel 

EZ UG- Education a LZX-6Q78 1 Users' Group: Eric Deeson. Highgate 

School, Birmingham B 12 9 DS. 

GUsrow ZX-Bomi Users' Club: Ian Walt, 107 Greenwood Road. 

Clarkston. Glasgow G76 7LW (04 1 638 124 1 ). Meetings: second and 

fourth monday of each month. 

Hassocks ZX Micro I ser Club, Sussex: Pdul King (Hassocks 4530). 

inverclyde ZX-81 Users' Club: Robert Watt. 9 St, John's Head, 

Gourock, Renfrewshire, PA 19 1PL [Gourock 39967). Meetings: 

Every other week on Monday at Greenock Society of the Deaf, Kelly 

Street, Greenouk. 

National ZX-80 and ZX81 Users' Club: 44-46 Earls Court Road. 

London WH liEJ. 

North Hertfordshire Home Computer Club: R Crutchfield. 2 

Durham Road, Stevenage:, Meetings: first Friday of the month at the 

Settlement, N a veils Koad, Letchworlh. 

North London Hobby Computer Club: ZX users' group meets at 

North Loridun Polytechnic. Unlbway Road, London N7 eech 

Monday, 6pm. 

Nottingham Microcomputer Club: ZX-flO.'fll users' group, G E 

rJasford. 9 Holme Close. The Pastures, Woodborough, Nottingham. 

Orpington Computer Club; Roger Pyatt r 23 Arundel Drive, 

Orpington, Kent, (Orpington 202B1). 



Poet Office Users' Club: Vernon Q Limn tain. Head Pual Officii, SI 

Martin's le Grand, London, El ! I 

Scunthorpe ZX Clubs C P Hazeltun, 26 Milestone Place, Bottesford. 

Scunthorpe; (0724 63488). 

Worle Computer Club: S W Rabotie, 18 Castle Hin+d. Wurle. 

Weslon-Htipfir-Mare BS22 9JW [Weston-super-Mare 5130GB). 

Meetings: Woodsp rings Inn, Worla, on alternate Mondays, 

ZX Aid: Conrad Roe, 25 Cherry Tree Avenue. Vuil-.U! WS5 4LH 

[Walsall 2546?) to cover Walsall and West Bromwiuh area, 

ZX-B0VZX81 Users 1 Club: PO Box 159, Km^lon-on-1 hbmea, A 

post til club. 



Overseas 

Belgium, France Luxembourg: Club ZX-BO^Bl, Roger Delil, Cliemin 

du Moulin 3B, B-1328 Ohain, Belgium: (322 6537 468) 

Denmark; Danmarks National ZX-80/81 Kluh(DNZK], Jens Larson, 

Skovmusevej 8,4200 Slsgnlnse. post giro 1 46 24 66. 

Eual Netherlands: Jonalhon Meyer. Van Spaen Straal 22,6524 H.N. 

Nijmesen; (060 223411). 

Germany; ZX-BO Club h a postal club; contact Thomas [enciyk. 

Hameln, Postfach 85 D-3250 Humein. Germany, 

bidonesia: Jakarta ZX-BO^Bl Users' Club, 73 Cnoc Criunain. Baile 

Atha, Cliath 1. 

Spain: Club National de Uauarius del ZX-B1 , Joseph-Oriol Tomas, 

Avda, de Madrid. No 203 207, 10, 3a esc, A Barcelona- 14 Espana, 

United Steles: Bay Aree ZX-8Q User Group, 2860 Las Aromas, 

ski find C A 9461 1, -— Harvard Gruup. Bui Ion Road. Harvard MA 

01451; [617 456 3967), 



SINCLAIR USER luiyl9R2 



11 



MICHAEL ORWIN'S ZXS1 CASSETTES 



QUOTES 

J ' M ic h a el Orwi n ' s £5 Cassette Two is ve ry g ood val ue . 
It contains 10 stolid well designed games which work, offer 
plenty of variety and choice, and are fun." 

From the ZX Software review in 

Your Computer, May '82 issue. 

"I had your Invaders/ React cassette ... I was 
delighted with this first cassette." 

P. Rubython, London NW10 

"I have been intending to write to you for some days 
to say how much I enjoy the games on 'Cassette One' 
which you supplied me with earlier this month " 

E.H., London SW4 

"... I previously bought your Cassette One and 
consider it to be good value for money!" 

Richard Ross-Langlay 
Managing Director 
Mine of Information Ltd. 



CASSETTE 1 
(eleven Ik programs) 

machine code: 

React, Invaders, Phantom aliens, Maze of death, Planet 

lander. Bouncing letters, Bug splat. 

Basic: 

I Ching, Mastermind, Robots, Basic Hangman. PLUS 

Large screen versions of Invaders and Ma2e of Death, 

Ready for when you get 16k. 

Cassette One costs £3 .80 



CASSETTE 2 

Ten games in Basic for 16k ZXB1 

Cassette Two contains ReversL Awari, Laser Bases, Word 
Mastermind, Rectangles, Crash, Roulette, Pontoon, 
Penny Shoot and Gun Command. 
Cassette Two costs £5. 




CASSETTE 3 

8 programs for 16k ZX81 

STARSHIP TROJAN 

Repair your Starship before 
disaster strikes. Hazards include 
asphyxiation, radiation, escaped 
biological specimens and plunging 
into a Supernova. 

STARTREK This version of the well known space 

adventure game features variable Klingon mobility, and 

graphic photon torpedo tracking, 

PRINCESS OF KRAAL An adventure game. 

BATTLE Strategy game for 1 to 4 players. 

KALAB RIASZ World's silliest card game, full of pointless 

complicated rules. 

CUBE Rubik Cube simulator, with lots of functions 

including Backstep'. 

SECRET MESSAGES This message coding program is 

very txJp qexi jf . 

MARTIAN CRICKET A simple but addictive game 

{totally unlike Earth cricket) >n machine code. The speed is 

variable, and its top speed is very fast. 

Cassette 3 costs £5. 



CASSETTE 4 7 games for 16k ZX81 



ZX SCRAMBLE {machine code) with 3 stages. 

Bomb and shoot your way through the fortified caves. 



GUNFIGHT 

{machine code) 



INVADERS 

(machine code) 








GALAXY INVADERS (machine code) 

Fleets of swooping and diving alien craft to fight off. 
SNAKEBITE {machine code) 

Eat the snake before it eats you. Variable speed, 
(very fast at top speed). 



LIFE {machine code) 

A ZX81 version of the well known game. 

3D TIC-TAC TOE (Baste) 

Played on a 4 x 4 x 4 board, this is a game for the 
brain, it is very hard to beat the computer at it. 



6 of the 7 games are in machine code, because this is much faster than Basic. {Some 
of these games were previously available from J. Stead man). Cassette 4 cost £5, 



Recorded on quality cassettes, sent by first class post, from: 
Michael Orwin, 26 Brownlow Rd„ Willesden. London NW10 9QL (mail order only please) 



12 



SINCLAIR USER July 19B2 




- AUTOMATIC 

- TAPE CONTROL 

The logical extension for £59.95 

the Sinclair ZX8I giving 

data retrieval & word processing 



The ZX99 Tape Control system is a sophisticated extension to 
the Sinclair ZX81 Microcomputer, providing remarkable 
additional capabilities, which allow both the beginner and 
expert access to a professional computing system without the 
expected expense. 

♦ DATA PROCESSING 

The ZX99 gives you full software control of up to four tape 
decks (two for reading and two for writing) allowing merging of 
data files to update and modify them. This is achieved by using 
the remote sockets of the tape decks to control their motors as 
commanded by a program. 

^ PRINTER INTERFACE 

The 2X99 has a RS232C interface allowing you direct 
connection with any such serial printer using the industry 
standard ASCII character code (you can now print on plain 
paper in upper and lower case and up to 132 characters 

per line,) 

♦ MANY SPECIAL FEATURES 

There are so many different features that it is difficult to list 
them all: 
For example: 

AUTOMATIC TAPE TO TAPE COPY: You can copy any 

data file regardless of your memory capacity (a C9Q has 

appro* 200K bytes on it) as it is loaded through the Sinclair 

block by block. 

TAPE BLOCK SKIP without destroying the contents of 

memory. 

DIAGNOSTIC INFORMATION to assist in achieving the best 

recording settings. 

♦ TAPE DRIVES 

We supply (and guarantee its compatability) a Tape Drive 
that works with your computer. 

♦ COMPUTER CASSETTES 

We supply quality (screw assembled) computer cassettes. 
Please enquire for any not shown: 




The ZX99 contains its own 2K ROM which acts as an extension 
to the firmware already resident in your ZXSl 'S own ROM. The 
ZX99's ROM contains the tape operating system, whose 
functions are accessed via Basic USR function calls. Each 
function has an entry address which must be quoted after the 
USR keyword. All of the functions can be used in program 
statements, or in immediate commands (i.e. both statements 
with line numbers and commands without them). 

There is an extension board on the rear to plug in your RAM 
pack {larger than 16K if required). The unit is supplied with 
one special cassette lead, more are available at £1 each 
(see below), 

COMPREHENSIVE USER MANUAL 
INCLUDED IN PRICE 

4|tZX99 SOFTWARE^ 

We now have available "Editor-99", a quality word processing 
program including mail -merge, supplied on cassette for £9,95, 
Also, following soon will be: 

* Stock Control * Order Processing 

* Sales Ledger * Debtors Ledger 



Business Accounts 



T?x Accounting 




COMPUTER CASSETTES 



C5 



CIO 



C12 



CIS 



C2Q 



C25 



cao 



QTY 



PRCE 



3Sp 



37p 



3Bp 



39p 



4lp 



4*0 



44p 



Add mm El 50 or 10% P& P 



TOTAL 



ITEM 



CASSETTES 



zx?° 



£312 Tope Drive 



EDiTGR-99 



CAS5ETTE (.SAP 



QtT 



See left 



PRICE 



59 °5 



24 00 



995 



1 OO 



P4P 



295 
1 00 ' 



50 



2Q 



Ch*quc/PO payable to Slorfcrase Ud 

S3 S3 



TOTAL 



ORDER FORM TO 

data-a//ettei 

LVpt- SWi 

4 4 Shroion Slreer. 

London NWl frUG Tel 01-258 0409 
Telephone tnquinei welcome 

NAME 



ADDRESS 



Charge my Acceis/ Vita Card no : 



SIGNED. 




Stephen Adams looks inside Sinclair's 
latest machine and finds it has a lot in 
common with the ZX-81 

Taking the lid off 
the Spectrum 



THE ZX SPECTRUM is very 
similar in shape and style to the 
ZX-B1 a net the re are many simi- 
larities. Sinclair has kept the 
original keyboard to save space but 
has provided a rubber sheet with 
moulded keys on it which fits over 
the top. The sheet is suspended over 
the flat keys — which on the ZX 
Spectrum are bigger than the ZX-81 
— so that when a key is pressed it 
bends to give some feel to the 
keyboard. 

That and the fact that the keys 
repeat if held down for longer than 
one second, even when using SHIFT, 
makes the keyboard much easier to 
use. The single keyword system has 
been retained and that seves 
memory, as all the Basic words can 
be stored as one byte. It also means 
that two SHIFT keys ere required to 
reach all the functions; one is celled 
CAPS SHIFT and the other SYMBOL 
SHIFT. They are at opposite ends of 
the keyboard and as they are often 



The keyboard is an input-output 
mapped device, as on the ZX-8 1 , and 
along with the the ZX printer, which 
is the same for the ZX-81 and the 
Spectrum network/RS232 interface, 
discs, loudspeaker, tape interface 
and border colours require only one 
address line to work, That means 
that you must make all of the lower 
five address lines a binary 1 to use 
your own devices. 

The input-output map access has 
bean improved greatly, however, 
with the addition to the Basic 
commands of IN and OUT. They give 
an instruction IN A(c} or OUT A(c] 
where registers BC give an address 
from to 65535. 

The memory-mapped addressing 
of the RAM/ROM occupies (MGK 
and the RAM 16K-3ZK on the basic 
16K model. There is provision for an 
extra 32K board to be plugged in to 
IC sockets at the back of the printed 
circuit board. The 48K version will 
have the board fitted but to add it 



the ZX-S1* The Spectrum has a 
2B-way double-sided edge connec- 
tor of the same style as the ZX-81. 
with the keyway on pin 5. That 
makes any input-output device com- 
patible with the ZX-81 but any 
memory-mapped devices would 
have to be rearranged. The edge 
connector also has a number of new 




The Spectrum is real value for money and 
easy to use. It has some peculiarities but 
they do not seem important when you look 
at what it can offer'. 



used one after another, it tends to 
slow the input speed as you are 
constantly swapping hands. 

For instance, RUBOUT and the 
cursor movements use CAPS SHIFT 
and +-* are SYMBOL SHIFT. It 
would have been a better idea to put 
both on the left-hand side, as they 
often need to be used together and 
could be pressed with one hand 
while the other searches for the 
appropriate key. 



14 



later it will cost £60. which 1 think is 
expensive. 

There would be no difficulty in 
adding extra ports to the memory 
map, as on the ZX-81, above 32K — 
on the basic version — but for two 
things. There is no RAM CS line, so 
that the extra RAM can he turned- 
off if required on the edge connector 
and the edge connector address 
lines have been moved to the outer 
edges so that it is incompatible with 



signals On it which are not explained 
in the manual, plus a video output 
and colour outputs for VDUs. 

All the voltages used on the 
Spectrum are also brought out, 
namely + 5V. -5V, + 12V and -12V. 
They are obtained from the same 
buzaing transformer as is used in 
the 16K RAM pack and most of that 
RAM pack seems to have been 
transplanted on to the Spectrum, 

The obvious additions to the 
circuitry are the PAL colour mixer 
under the metal can which contains 
the video modulator and the fact 
that two crystal-controlled 
oscillators are used, one for the 
ULA, which controls the screen 
among other things, and the other 
for the colour mixer. The HrnHz 
clock for the ULA is also used to 
drive the Z-60A microprocessor 
after it has been reduced to 3.5mHi. 
That is 0.25mHz faster than the 
ZX-fll. The Z^OA has also been 

SINCLAIR USER July 1902 




spectrum 
radio 



freed of the job of putting-out the 
screen — by the ULA — and so no 
longer requires the commands 
FAST or SLOW, as it works at top 
speed all the time except when BEEP 
or PAUSE is used. 

PAUSE and BEEP both cause the 
Z-8QA to stop for a time determined 
by the programmer end so it will do 
nothing else while those commands 
are being done. BEEP commands 
should be kept short in a program 
for that reason; 0.01 seconds is a 
good speed to PKINT AT and BEEP at 
the same time. 

As for programming the 
Spectrum, it can be considered as 
an extension of the ZX-B1 Basic, The 
PAPER, INK, BRIGHT and FLASH 
commands for each character 
square ere stored in a memory map 
above the dots for each character. 
They are all stored in one byte per 
character and can be read by the 
Basic word ATTR and altered either 
by Basic commands or PQKEs. 

The dot screen is a different 
matter, however, and cannot be 



altered so easily , as the dots are 
s tored in pecu liar order , so you h a ve 
to use the graphics commands — 
which can define all the dots on the 
22 line by 32 character screen 
available to the user — or the 
SCREEN command. 

There can be only two colours for 
each character square, one for the 
foreground (INK) and one for the 
background (PAPER), but they can 
b e any one o f eight c olour s . They c an 
also be inverted at a rate of one per 
second continuously, square by 
square (FLASH) or have two 
intensities of colour (BRIGHT), 

The s c r sen t akes up 6 . 9 1 2 bytes of 
the 16K memory and the system 
variables take up another 738 bytes. 
The rest of the memory is not free for 
the user to use as 11 other areas 
float above location 23733 and can 
expand and contract as required by 
the Spectrum. 

The program and variables are 
sandwiched in the middle of those, 
so REM statements cannot be used 
for machine code. There is an area, 



however, which can be used for 
machine code programming above 
RAMTOP which is ignored by the 
Basic and its length can be defined 
by the user, 

The user-definable characters 
area is stored above that so they can 
be kept from program to program. 

There are many tape 
arrangements which can be made 
with the Spectrum. The program, 
strings or machine code can all be 
SAVEd, LOADed and VERIFYd 
separately. The variables and 
screen can also be stored on tape 
but cannot be VERIFYd. As each is 
SAVEd, a messsage to start the tape 
recorder will appear and wait for 
you to press a key. That is a very 
good example of the user- 
friendliness of the machine and 
most of the errors appear with 
similar messages. 

SAVEing or LOADing causes the 
border to flash red and green or red 
and blue, depending at which part of 
the tape you are looking. All of my 
tape programs LOADed correctly 
and I was surprised with the 
difference in speed between it and 
theZX-61, 

I have been able to deal with only 
a few subjects, There is so much 
more to learn about the Spectrum 
from the manual that it would 




become a series if I did not stop now. 
The Spectrum is real value for 
money and easy lo use. It has some 
peculiarities but they do not seem 
important when you look at what it 
can offer. With disc, networking 
facilities and RS232 interface it is a 
great improvement on the ZX-81 but 
it cannot replace it. as the price of 
£129.95 will still be a little daunting 
to those who wantlotrya computer 
for the first time. 



SINCLAIRUSER July 19H2 



15 



"THE BESTZX81 BOOK 



> t 



THE 

ZX81 

COMPANION 



cb ffl ss p 



STORY, 



Bob Maunder 



L1NSAC 



If vou have a Sinclair 2X81 and want to use it to its full potential 
then, as the experts ha ve all agreed, this is the book for you. It 
contains detailed guidelines and documented programs in trie 
areas of gaming, information retrieval and education, as well as a 
unique listing of the8K ROM for machine code applications. 

far and a way the best . , . once again Lmsachas produced the 
■ book for the serious end of the market'.- Your Computer, 
November 138 1 , 

TheZXSl Companions 3 most professional product ... with many 
good illustrative programs, tips and warnings' -Education 
Equipment, October 1981. 

Bob Maunders attempt to show meaningful uses of the 
machine is brilliantly successful . . . thoughtfully written, detailed 
and illustrated with meaningful programs To conclude - the 
book is definitely an outstandingly useful second step for the ZX8 1 
user. - Edvc9tionetZX8Q/3f Users' Group rVei#s fetter, September 
1981 



Send your ch eq ue for C? ,95 ( i nc I udes U K p & p) t o : 



1 lltJG Af* /CI II ea Barker Road, Linthorpe, 
LI PlDfW \OUJ Middlesbrough TOSSES. 



ISBN09G7211 01 1 



Price £7 95 




quality games and special techniques 

the widest range available from one supplier 1 



Music 

Music 
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ZX Spectrum 

20 Programs £6.95 

The ZX Spectrum has brought advanced 
computing power into your home, The 
Cambridge Colour Collection, a book of 
20 programs, is all you need to make it 
come alive. 

No experience required. Simply enter the 
programs from the book or load them from tape 
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Amazing effects. All programs are fully 
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Entirely original. None of these programs has 
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• Lunar Landing. Control the angle of descent 
and jet thrust to steer the lunar module to a safe 
landing on the moon's surface. 

• Maze. Find your way out from the centre of a 
random maze, 

• Android Nim. Play the Spectrum at the 
ancient game of Nim using creatures from outer- 
space. 

• Biorhythms, Plot the cycles of your 
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Sonne would say this is not a game at all. 

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• Morse. A complete morse-code training kit. 
This program will take a complete beginner to 
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• Maths. Adjustable to various levels, this 
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improve their arithmetic. 

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• Home Accounts. Keeping track of your 
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SINCLAIHUSER July 1962 



17 




IB 



SINCLAIR USER JulylWZ 



FULLER FD SYSTEM £39.95 

Professional Keyboard & Case for Sinclair ZX81 & ZX Spectrum 




The ZX81 fits inside 

The tough ABS injection moulded 
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The ZX16K Memory Module will fix 
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By removing the ZX PSU from its case 
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INSTALLATION 

Simply unscrew the ZX printed circuit board from 
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We also manufacture a mother board which allows 
expansion to the ZX memory and 1/0 facilities 
WITHIN the case, as well as our power supply unit 
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'^0 






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12.95 






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Mail to FULLER MICRO SYSTEMS, 

The ZX Centre, Sweeting Street, Liverpool 2. England, U.K. 

SAE for more details — Enquiries: Tel. 051-236 6109 



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"Best explanation I've seen,(| 
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Available as a quality paperback, loO pages, £9.75 including post pack 
ana" VAT. 




UNDERSTANDING YOUR ZX81 ROM by Ian Logan 

Dr. ian Logan was the 1981 winner of the Rosetta Stone Award* given 

to the best independent product, software package or application for the 

Sinciaif ZXSO or ZX81 for his perceptive insights into the way the ZX81 ROM 

operates. 

This book explains ZXSO Machine Language m terms of the ZX81 ROM, 

giving numerous examples of routines from the ROM. and explains the 

structure and organisation of the ROM, including routines from the ROM 

you can use yourself 

A special section explains how to use machine code routines in your own 

BASIC programs. 

Available as a quality paperback, 164 pages. E9.75 incluaing post pack 

and V At 



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ZX81 ROM DISASSEMBLY PARTS A & B 

Dr. Logan is also the author of these two titles (see above) which are an 

invaluable source of information for the serious ZXB1 Machine Language 

programmer 

Part A lists all locations and subroutines in the ROM from OOOOH to OF54H 

and covers all the operating functions of the ROM except the floating 

point calculator, 

Part B iists aH locations from QF55H to 1DFFH and covers all the routines 

involved in the evaluation of an expression and a detailed explanation 

of the floating point calculator'. Co-authored by Dr. Frank O'Hara. 

Part A 3Q pages, 17.8Q including post, pock and VAT 

Part B. 64 pages, tfl.80 including post, pack and VAT. 

Other titles available: 



Hot only 30 programs lor Itie Sinclair ZX01: IN 

Not only over 30 programs, from arcade games to 
the final challenging Draughts ploying program. 
which all fit into the unexpanded Ik Sinclair ZX81 but 
also notes on how these programs were written and 
special rips! Great value! 
120 pages, t? 75 



Complete Sinclair ZXfll tasic Court* 

The Complete Basic Course is a 240 page in-depth 
comprehensive text tar complete beginners and 
experienced programmers. Ovef TOO programs and 
examples illustrate the use and possibilities of tr*e 
Sinclair ZX8L This is an invaluable reference guide for 
an ZX81 owners 
256 pages. £18 30 



Special Discount for ordering more than 1 title 

If you order more than one title at a time, you get a discount of BOp per additional title: 
If you order 2 books, deduct 80p from the total order 3 books and deduct £loO; order 4 books and 



deduct il2.40! 



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new 




Smith adds to 
micro range 



W H SMITH expects to be 
selling another computer 
by the end of the year. It is 
talking to a number of 
manufacturers about 
Stocking their micro3 to 
add to the ZX-81 which it 
began selling last 
September. 

John Rowland, market 
development manager, is 
giving nothing away about 
which machine it might be 
but expects a decision to 
be made in August. 

It is the next major step 
in the company's move into 
the home computer 
market, which it sees as a 
major growth area. It is 



already extending the 
number of branches 
selling computer goods 
and increasing the amount 
of selling space, 
particularly in the larger 
branches. 

"We sell 50 lines of 
software and are 
increasing that all the 
time. We think we are 
ready to take the next step 
in offering a new 
machine," Rowland says. 

He added that when the 
new product is launched it 
is hoped it will be accom- 
panied by a full range of 
software. He expects that 
by next year the company 



Clive to run in 
half-marathon 



CLIVE SINCLAIR'S energy 
seems to be endless. Not 
only is he able to master- 
mind one of the most suc- 
cessful computer com- 
panies in the world — he 
has enough strength left to 
run marathons. 

He has already run one 
distance of more than 26 
miles and now he is to take 
part in a half-marathon 
being organised as part of 
the 1982 Cambridge 
Festival. 

Sinclair Research is 
sponsoring the event with 
£5,000 and it is expected 
that 2,000 competitors will 
be taking perl, including a 
number of top-class 
runners. 

The race will be held on 
Sunday, July 18 and will 



follow a course through 
the city's historic streets, 
The company, which is 
based in Cambridge, seas 
the sponsorship of the race 
as part of supporting the 
cultural life in the city. It 
will also be sponsoring a 
concert in King's College. 
Cambridge as part of the 
festival. 




John Hawluntl, market develop- 
ment manager of WH Smith 

will be selling more than 
100 lines of software. 

Rowland says that in the 
next few years W H Smith 
would probably like to sell 
about three machines with 
a full range of hardware 
add-ons and software. 
After that, he thinks the 
market will probably go 
the same way as the 
record market, with some 
retailers concentrating on 
hardware and others on 
software. 

Of the hardware 
market, he says that 
Smith's entry will depend 
on manufacturers agree- 
ing to a standard 
interface. Without that il 
would not be possible to 
generate sufficient sales 
to make it worthwhile. The 
retailer is locking for high- 
volume sales, which is why 
it chose to enter the 
market with the ZX-81 . 

Rowland added that 
Smiths is also looking at 
the possibility of becoming 
a software publisher. The 
company already receives 
many suggestions each 
week. 



ZX fairs 
spread 
to North 

THE FIRST exhibition for 
ZX users to be held in Bir- 
mingham is attracting a 
great deal of interest, 
despite its clash of dates 
with the Personal Com- 
puter World show in Lon- 
don. The organiser. Eric 
Deeson, says that about 40 
of the major companies in 
the market are taking 
space. 

The idea for Microscene 
Brum 82, on Saturday. 
September 11, resulted 
from the successful ZX 
Microfairs in London. 

"Many people said how 
inconvenient it was having 
to go to London so we 
thought we would try for a 
regional show," Deeson 
says. He is hoping to at- 
tract people from all over 
the Midlands and further 
north. 

Meanwhile a general 
microcomputer fair is 
being held at Manchester 
on July 24 and 25. It is 
being held in conjunction 
with the University of 
Manchester Institute of 
Science and Technology at 
Sackville Street, Man- 
chester and is aimed at the 
education and small 
business markets. 



Brain power wins ZX-81s 



TWENTY-THREE regional 
winners in this year's 
Mensa Superbrain com- 
petition have been award- 
ed ZX-81 s. The awards 
were prompted by Clive 
Sinclair's involvement 
with the British Mensa 
Society, of which he is 



chairman. 

The competition is an 
annual event and is set to 
be a test af intelligence 
rather than memory, as in 
Mastermind and Brain of 
Britain. It is usually run in 
conjunction with provin- 
cial newspapers on a 



with the 
ners pro- 



regional basis, 
regional 
ceeding to the final. This 
year, for the first time, ex- 
tra sections were organis- 
ed through the indepen- 
dent local radio network, 
which provided five 
regional winners. 



SINCLAIR USER fu Jy 1 982 



21 




Radio Sinclair 

There seems to be no limit to the uses which can be found for the 
ZX-81 Here Julian Moss reports how it has been of help in 
amateur radio. 



A MATEUR RADIO is a hobby as 
f\ old as radio itself. Ever since 
* ■'■Marconi sent the first 
transmission across the Atlantic, 
radio amateurs have been ex- 
perimenting with new modes of com- 
munication and. in the process, mak- 
ing friends across the world. 

Many of today's radio amateurs 
use commercially-made equipment 
but there is still a good deal of ex- 
perimenting, in aerial design for ex- 
ample, and at very high frequencies. 
Like any technical hobby, there are 
many uses for a computer and the 
ZX-81 has found its way into many 
radio shacks. Its uses fall primarily 
into three areas — information 
storage and retrieval, mathematical 
and scientific programs, and real- 
time on-t he-air applications. 



Programs in the first category are 
fairly straightforward. One ex- 
ample is an index of radio stations 
contacted or heard. Every radio 
amateur has his own call-sign, in 
which the first two or three 
characters denote the country — 
for example, the G4 in the call-sign 
G4ILO indicates England. Since a 
typical ham may make thousands of 
contacts in e year, it is impossible to 
remember every one. 

By storing on the computer each 
call-sign, along with the operator's 
name, town, the date and perhaps 
other details, it is possible to recall 
immediately whether or not a 
station has been contacted 
previously and to see the details of 
the contact. 

The data can be sorted into call- 





sign order, to see how many coun- 
tries have been contacted — useful 
since many amateurs compete for 
certificates which are awarded for 
contacts with, for example, 100 
countries. 

Another use for the computer ia to 
compile an index of technical 
articles in radio and electronics 
magazines. Most radio amateurs, 
like home computer enthusiasts, ac- 
cumulate magazines devoted to 
their hobby. It is frustrating to 
search issue after issue looking for 
an article you remembered reading 
a few months ago, If a description of 
each article is stored in the com- 
puter, together with the name of the 
publication, its issue date and the 
page number, it is possible to have a 
program which will search the 
descriptions and produce a list of all 
the articles relating to a particular 
topic. Typically, more than 300 
references can be stored on a 16K 
ZX-^l. 

Another facet of amateur radio is 
contests. On some weekends, 
amateur operators from all over the 
world try to make as many contacts 
as possible in a given period, usually 
24 hours. The scoring varies from 
contest to contest but usually is 
based on the number of contacts 
made and the number of country 



22 



SINCLAIR USER JuJyl982 




amateu 
radii 



prefixes, or even the total distances 
over which the contacts were made. 

Keeping the score is an ideal job 
for a computer, which can also log 
each call-sign end display a 
message if a station has been con- 
tacted previously in the contest. 

On the technical side, there is a 
vast number of uses for the ZX-B1. 
Two examples are aerial design, 
whan the computer can be used to 
work-out the dimensions of an aerial 
for a particular frequency, and even 
to calculate its theoretical perfor- 
mance; and the design of electronic 
circuits. 

American magazines publish pro- 
grams of that nature frequently. 
Those programs are usually written 
for the most popular home com- 
puters in the U.S., such as the 
TRS-80. but it is fairly straightfor- 
ward to convert them to run on the 
ZX-81, the main differences being 
that the TRS-80 does not require the 
word LET in an assignment state- 
ment and that it allows multiple 
statements on one line. 

Another popular application is 
Oscar tracking, Oscar stands for 
Orbital Satellite Carrying Amateur 
Radio. It is a satellite designed, built 
and paid for by radio amateurs, and 
launched by NASA on their behalf. 
The satellites pick up amateur 
transmissions on one frequency and 
re-transmit them on another, allow- 
ing communication over distances 
which might otherwise not be possi- 
ble. 

To use Oscar, it is necessary to 
know where it is at any given time 
and so a program can be used to 
predict when the satellite is 'visible' 
from a location and in which direc- 
tion to point the aerials. 



One problem which radio 
amateurs soon encounter when they 
put a computer in the shack is in- 
terference. The ZX-81 radiates a 
good deal of radio noise, which is 
picked up by the receiver and can 
easily obliterate weak signals. 
Usually it is necessary to screen the 
case carefully, using aluminium foil, 
and to filter the lead from the power 
supply. The RAM pack must be 
screened as well. 

The reverse of that situation can 
also occur, when RF from the 
transmitter interferes with the 
operation of the computer, This is 
not usually a problem with the 
ZX-81, however, although the tele- 
vision used for the display can be af- 
fected sometimes. 

Once those problems have been 
overcome, the computer can be used 
on-the-air to send and receive 



program the computer to scan the 
band for stations using Morse code 
and reply to them automatically. 

It is possible to generate Morse 
code without using additional hard- 
ware, using the cassette output 
socket. That output can be fed into 
en amplifier, or recorded on tape for 
Morse practice. It is also possible to 
feed code into the cassette input 
socket, decode it, and display the 
text on the screen. The main diffi- 
culty is that, in SLOW mode, the 
ZX-81 spends about 15 out of every 
20 milliseconds displaying a picture 
on the TV and that interferes with 
the generation or reception of the 
code. Thus programs for Morse or 
RTTY usually are written to run in 
FAST mode. 

A Morse decoder has been 
developed which will display on the 
screen code which is fed into the 
cassette input socket at a suitable 
level. Since it runs in FAST mode, 
the text can be read only once the 
program stops when the screen is 
full, or once the BREAK key is press- 
ed. Noise and interference will 
upset the decoding and the signal 
should go ideally through a narrow- 
band filter, so that only the wanted 
signal is fed into the ZX-81, 

The program uses a short USR 
routine to read the cassette input 
port, The routine is 24 bytes long 



The computer can be used on-the-air to 
send and receive Morse code and radio- 
teletype signals'. 



Morse code and radio-teletype 
signals, and even to control the sta- 
tion. Many of the new amateur radio 
transceivers use a microprocessor 
to control the various functions such 
as frequency and mode, and the 
various control lines are brought 
out to a socket at the back. 

Using a suitable interface, it 
would be possible to program the 
ZX-81 to scan selected frequencies, 
perhaps to record whether or not a 
signal is present, to build a picture 
of amateur band activity at various 
times of the day, or to monitor the 
strength of particular distant 
stations. It would even be possible to 



and is stored in the first REM state- 
ment of the program. The easiest 
way to enter the routine is to type-in 
a REM with 24 characters in it and 
then to POKE into locations 16514 lo 
16537 the values given in the table 
following the program listing. The 
routine returns a value of O if no 
signal is present at the input port, or 
a positive number if one is present. 
There is a Sinclair Amateur Radio 
Users' Group in the U.K. Anyone in- 
terested should contact Paul 
Newman, G4INP 3 Red House Lane, 
Leiston, Suffolk, IP 1 6 4IZ. enclosing 
a stamped addressed envelope for 
details. 



SINCLAIR USER July 1 982 



23 



NEED MORE MEMORY 
FOR YOUR ZX81...? 





|ZX 16K RAmM 





16K-£19.95 



jjt FREE 5JC 

16k sank Account cassette by 
Futgresoft +£3 Trade in on our 16k unit 
for a 64k unit if returned within 6 months. 



64K-E47.95 



we at Pretoriua Syetame have commissioned a leading vloctronici company to dasign 
for us a low coat VERY high quality memory modulo specifically far the ZXB1. It can 
be uisd in any expansion system end simply plugs into the back of your ZXB1 and 
as such is fully compatible with the ZXB1 printer. 

The 16k module will give you 16 times mora memory and is finished in ABB 
plastic Their is also a 64.k version which vvil I provide you with a pure 61k of 
program POWER. This amazing achievement is packed into exactly the same casing 
as the 16k module and looks identical. Note: these units are BRITIBH made and 
should not ba confused with low quality imports that overheat and nave sloppy 
connectors. 

Nothing more to pay! Prices include VAT + FREE postage Covereeas orders +£&) 
14 days money back offer if not satisfied + 6 months warranty. 

Your order is recievod at S.30 and ia despatched by IE. 3d the aame day. 



PLEASE SEND ME : 

□ ate . 

Name 





Quantity 


Price 


Total 


16k 




19.96 




64k 




47.96 





AddreSS 



Payment to: PBETORIUB SYSTEMS 

Mail to; B.C.M. BOX 7977. WC1N LONDON. ENGLAND. 



24 



SINCLAIR USER July 1 96? 



new 
users 




Nicole Segre finds that, despite her reservations, 
understanding the ZX-81 is only a matter of time. 

Discovering the adult 
charms of the ZX-81 



I COMPLAINED at some length 
last month about the upheavals 
caused in the household by my 
son's purchase of one small, 
seemingly innocuous electronic 
machine called a ZX-B1. What 
distressed me most was that ha and 
his friends, all mere babes in arms, 
seemed possessed of a technical 
skill end expertise with regard to 
computers which left me feeling 
decidedly pas3e. 

1 have determined to remedy all 
that. II is important, in my view, not 
only to keep up with the times but to 
teach all those uppity youngsters 
not to under-estimala their mothers* 
Accordingly, I waited for a short 
pause between a game of Star Bash 
and a game of Clonk! and obtained 
my son's permission to tinker with 
his Sinclair during those hours 

&[NCLAIR U SER luly \ 982 



when attending to his education 
kept him away from more pressing 
matters. "Is there anything I must 
not do?" I enquired anxiously. "No, 
it's ell right." he said. "Computers 
are idiot-proof," 

Letting that go, 1 set to work the 
next morning and I made an 
astonishing discovery — it's easy. 
All you have to do to use a ZX-81 is 
fellow the instructions and, believe 
me, if 1 can follow the instructions, 
anyone can. To be honest, I am a 
wonderful human being with many 
precious gifts but a way with 
inanimate objects is not one of them. 

So far as I am concerned, sexual 
equality stops short of changing 
lyres or replacing washers and, as 
for electricity , I am like the man who 
thought there was cold electricity 
for refrigerators and coloured 



electricity for traffic lights. 

Yet in no time at a)l I was able to 
use a sophisticated piece of 
equipment, even to the extent of 
programming it to tell a silly joke. 
Now, I am jus I letting-up before 
racing on to looping, graphics and 
organisation of memory, which 
sounds just the kind of Ihing I need. 

Having said that, however, I can 
admit freely that it has not all been 
plain sailing. In fact, at first it 
seemed as if the whole self- 
improvement plan would never get 
off the ground. A 13-year-old's 
bedroom is probably not the best 
place to conduct an important 
research project of this kind and niv 
son's bedroom possesses sufficient 
electrical wiring to knit a 
fisherman's sweater- 

continued on page 26 



25 






■* 



u 

i 



con United from pane 25 

You are ready to begin, the 
manual said, when a K appears in 
the bottom left-hand corner of the 
screen but for that to hoppen I had 
to find the socket in which to plug the 
sock fit in which to plug the plug. 

Several hours later, I emerged, 
hot and dusty, from under the bed, 
and there was the magic K. Fingers 
at the ready, I turned once more to 
the excellent manual, which I 
cannot praise enough for its clarity 
and wealth of incidental detail. I 
had no difficulty with adding 2 + 2, 
cursors, the history of computer 
languages and how to erase 
mistakes but the chapter on using 
the computer as a calculator caused 
a twinge of anxiety. 

I don't even use a calculator as a 
calculator. I know what a square 
root is, and even pi. although I can- 
not remember when I last used it; 
but integers and exponential 
functions? They must have done 
those while I was away from school 
with chicken pox. Anyway, having 
managed without them for so long, I 
thought I might continue to do so and 
skipped to the next section. 

Thai looked more promising, 
being all about the price of eggs. 
Those I do use and although I can 
usually work out their price, give or 
take a few pence, in my head, it 
amused me to let the computer do it. 
It could even, the manual said, tell 




shall soon be able to dispense with 
her services? 

Things took a downturn, however, 
with the price of butter and yeast. 
Having missed a vital piece of 
information about semi-colons — 
buried treacherously as I later 
discovered in that frightening mass 
of higher mathematics — 1 suddenly 
los t control. A stern S — for Stupid? 
— kept appearing to say I had it all 
wrong and when 1 attempted to put it 
right, everything went from bad to 
worse. 

The trouble is that I am used to a 



'Unnecessary though a ZX-81 may be, 
what a marvellously clever and obedient 
little chap it is' 



me the square of the cosine of the 
price of one egg, should 1 aver want 
it. Well, you never know. I was glad, 
too. that the manual catered for the 
eventuality of my housekeeper 
rushing in, full of concern, and 
crying in that delightfully old- 
fashioned way of hers: "Glory be, 
eggs have gone up to 61 pence a 
dozen." 

What worries me. though, is how 
am I going to tell the kind soul that, 
thanks to my handy little computer, I 



typewriter keyboard, not one which 
moves things about and has about 1 2 
instructions per key and erases 
backward to boot. I knew you could 
pull out the plug and start again but 
that seemed a little drastic. It 
reminded me of my one and only ski- 
ing holiday when learned to 
negotiate a slope, more or less, but 
not to s top . To do th a t , I would th row 
myself into the first convenient 
snowdrift but I always thought 
there must be a better way. 



Eventually, it all came clear to me 
and I was chugging along again 
happily. At one point I even thought 
that, together, the computer and I 
would crack that eternal problem of 
the length of a piece of string but it 
proved to be more a matter of 
whether Mr Smith was shorter than 
Mr Smythe. 1 don't think I had that 
correct. By then my earlier 
struggles had worn me out and, 
besides, there was a good film about 
to start on the other channel. 

My studies may not be very 
advanced but I see now how one 
could become very involved in all 
this, From the start, 1 have 
wondered what possible use a 
computer such as my son's could be 
and 1 slill don't know — but who 
cares? Pressing buttons is fun. 

Unnecessary though a ZX-81 may 
be, what a marvellously clever and 
obedient little chap it is. Do this and 
do that, the manual says, and the 
computer will do this and do that — 
and it does what else in life is so 
simple and so satisfying? 

Anyway, 1 could not slop now. All 
kinds of fascinating things have 
caught my eye — measles programs. 
Venusians with eight fingers and no 
thumbs, flowcharts — and I must 
investigate- If anyone wants me in 
the next few days, please speak to 
the housekeeper. 



26 



SINCLAIR USER fu/ylSfi2 



READ OUT FOR 

^ SOFTWARE ' 

& BOOKS 



1?F AH OT TT PT TUT TCl4T\m T TH 8C * m P Roa(J - Farnboraugh. Hampshire, GU24 SEW 
I\LAU"UU 1 F UlJLlOnil>J\J LuLLJ Telephone: 0252 510331 3 Telex 858001 GOWER Q 

THE ZX BOOK CLUB 

The ZX81 is the world's biggest selling computer and, just announced, is its 

big brother, the ZX SPECTRUM. 

For value for money, these two computers must be the best "computer" buys on the market - but - to get the 
most from them, every owner, and prospective owner, needs a library of books for programs and operations, 

Read-Out has selected the following bestselling books and can supply 

from stock. 



For the Beginner:- Getting Acquainted with your 
ZXB1 by Tim Hartnell, containing over 80 programs. 
34 Amazing Games for the ZX81 by Alistai r Gou Hay, 
wh ich shows you what you can do with only 1 K of 
memory. 49 Explosive Games for the ZX81 by Tim 
Hartnell which describes games listings for the 
memory sizes IK - 8K. Coming Soon! Learning to Use 
the ZX81 by Robin Bradbeer and Learning to Use the 
ZX Spectrum by Robin Bradbeer - two new books in a 
new series designed to help the first-time user (both 
due August/September 1982). The Personal Computer 
Book 2nd edition by Robin Bradbeer - an introduction 
to the world of microcomputing which is generally 
regarded as the best available. 

For the Enthusiast:- Mastering Machine Code on your 
ZX81 by Toni Baker will help you develop your 



programming skills to a point where you can really 
use machine code easily. The Gateway Gukte to the 
ZX81 and ZX80 by Mark Charlton is a "doing" book 
describing each function and statement in turn, 
illustrates it in e demonstration routine or program 
and then combines it with previously discussed 
material. The 2X81 Pocket Book by Trevor Toms 
covers the use of the ZX81 in detail and leads the 
reader into a clear understanding of programming. A 
brand new book is 20 Simple Electronic Projects for 
the ZX81 by Stephen Adams which can really put 
yourZX81 to practical use in a number of interesting 
electronic projects - thermometer, burglar alarm, 
voltmeter etc. Byteing Deeper into your ZX81 by avid 
Johnson-Davies - the bestseller which tells you how 
to get to grips with yourZX81 and with 39 programs 
to match! 



.*£?* 



y--4 



& ThePersor mast; THE 

GAMES ^t cc GUIDE 

■--• 3«1 I 

2X80 I 






'«*>•,, 






TlrnHareni 



MAflK CrU 

■ 

T ' ?0 Pjjof 



**£;•**. 
**-* 



*"»*p*-, J 



Ha fff 



la. 



'"it* 




Order through READ-OUT PUBLISHING COMPANY LTD 




8 CAMP ROAD, FARNBOHOUGH, HAMPSHIRE GU24 6EW- 
24 hour answering service Telephone: 0252 510331/2 



Name 



Address 



Make cheques payable to Road-Out Publishing Company Ltd. 
I enclose my cheque for £. 



Q 



Please debit my Access □ 
Number r 







M .I 



Signed. 
Dale 



Please send me : copy.ies of : 

All prices include postage. 

□ Getting Acquainted with your ZXJ1 9 £6.95 
i J* Amiiing G*m« tor the 1K ZX81 . fb*i 
| ; 49 EhoIgmm Gamw 1or Itw ZX81 ■■ £6 « 
G Uinring to Use the ZX91 i £5 95 

(due Aug/Sep) 
n Learning Id Uh the ZX Spectrum m £5 95 

4dua Aug/Sep) 
| j The Perianal Computer Booh '.a E7.55 
H Mistering Machine Cede en Veor 2X91 1 £8 SO 
Q Get*W»r Guide ta th* ZX81 :u £7 45 
r i The ZX|1 Pocket Beak fa £5,95 
PI » Simple Electronic Gem** for the 2X11 f £7 45 

J Byteing Deeper into your ZXIl \a it 4S 

IX' i 



I 
I 

I 
I 
I 



SINCLAIR USER Juiy1962 



27 



Reader survey 



1 Into which range does your age fall? 

Under IB □ 16-25 □ 26*35 □ 36-45 D 46-55 D 56-65 □ Over 85 □ 

2 Are you in employment? yes/no 

If yes, give type of employment » . . . 

[fno, state whether student, retired, or whatever 






3 Into which ranges does your income fall? 

Leas than E 5,000 D £5,000 to £10,000 £10.000 to £15,000 □ £15,000 to £20,000 □ 

More than £20,000 □ 

4 Do you own a Sinclair computer? 

Which one? ZX-60D ZX-81D Spectrum D 

How long have you had it? Less then one month □ 

One to six months □ Six to 1 2 months U Longer than 12 months D 

How did you buy it? Mail order D WH Smith D Second-hand D 

If you intend buying anodier model, which one? . . . . 

If not, do you use someone else's? yea/ no Do you intend buying one? yes/no 

Which one? ZX-BO □ ZX-61 D Spectrum □ 

5 Do you use any other system? yes/no 

Which one? - ■ . 

6 Do you own any peripherals? State makes. 

Cassette player □ . . . . . 

RAM pack □ - ■ • • • ■ 

Printer D - . . . - 

Keyboard D * 

Motherboard D 

Any other hardware □ 

How did you buy them? Mail order through Sinclair User □ 

Other mail order □ Microfairs □ WH Smith □ 

Other sources, give details. 



2B SINCLAIR USER July 1982 



* + 



reader 
survey 



To help us plan for the future and to ensure that we maintain the high standards which Sinclair User 
has achieved in its first three issues, we would be grateful if you complete this questionnaire. 

None of the questions is difficult and all information will be treated in confidence. 

Please tick the boxes or write your answer in the space provided. 



yea/no 



7 Do you buy any software? 

What types ?....„ 

From where? ............... 

How much do you spend each month?. 



8 Do you have a special monitor or television? yea/no 



9 For what do you use the Sinclair computer?. 



■ ■11-t-LI-IB, 



**fci++Pl + 



What other uses do you intend to make of it? . 



r i i + + p ■ 



10 Are you a member of a computer club? yea/no 
la it at school or private? ............ 



1 1 How long have you read Sinclair User?. 

Where do you obtain it? 

What do you like about it 



i ■ * - - * * « m » * w * » « ■ 



What do you not like?. 



How could it be improved?. 



1 Z What othe r c ompu to r magazines do you read? 

Personal Computer World D Computer and Video Games D Your Computer Q Practical Computing □ 

Microcomputer Printout □ Windfall D Educational Computing □ Microdecision □ 

Which Micro? □ ZX Computing D Sinclair Programs D Popular Computing Weekly D 

Computer Today □ 

Any other? State which , 



SINCLAIR USER July 1962 



29 




THE 
PROFESSIONAL 

ZX81 KEYBOARD 



All -you -need Keyboard Kit £28,95. 
Case only £15.00. 



AH prices inclusive of VA T, postage and packing, 
Pfease a flow 21 days for detivery. 



Plug in — no desoldering. 

Space bar linked to space key. 

Full travel keys. Six spare keys for 
your own use. 

Case available to hold keyboard and 
ZX 81 microcard. 

16K RAM pack clamp 
supplied with case to 
eliminate white outs!! 




COMPUTER KEYBOARDS DIV. 
DEAN ELECTRONICS LIMITED 

GlendalePark FembankRoad Ascot Berkshire England 
Dial-a-leaflet 03447 5661 Telex B49242 



personal computer sof twanp 



ZX81/16K SOFTWARE 



'STARTREK" £4.95 

16K STARTREK: Exciting space adventure game including 

klingons starbases, phasors, 8 x 8 galaxy, 4-levels of play, long 
and short range scanners, etc. 

"SUPER-WIMPUS" £4.95 

16K SUPER WJMPUS: Can you hunt and catch the 
mysterious wumpus in his underground labyrinth? Intriguing 
underground adventure. 

"GRAPHIC-GOLF" £4.95 

16K GRAPHIC GOLF: Try out your golfing expertise, on the 
computer's golf course, 18 different graphically display holes. 
Hazards, include lakes, trees, wind, rough etc. 

"GAMES PACK 1" £4.95 

16K GAMES PACK 1: Fantastic value for money, nearly 50K of 
programs on one cassette. Five games including "Heal Time 
Graphic" Lunar Lander, Starwars, Hammurabi, Minefield, 
Mastermind. 

ZX ZOMBIES" £4.95 

16K ZX-ZOMBtES: Can you escape the manrauding, rtOn- 
eating ZX ZOMBIES as the chase you for your FLESH!!! Eight 
rounds of play, highly addictive. 



SILVERSOmDep. SU7I 

35 Bader Park, Bowerhill, 
Melksham, Wiltshire, 



□ 



ZX-ARCADE ACTION 
NEWirMUNCHER!!" 



£5.95 



At last Pacman for your ZX-91 , all the arcade features plusl? 
software for the QS character board. 

D "SPACE-INVADERS" £4.95 

Simply the best yet, the closest thing to real Invaders on (he 
ZXB1. Full arcade features! including 1 or 2 player option and 
software to drive the QS character- board. 

□ "ASTEROIDS" £5.95 

Authentic representation of the arcade game including L, R, 

thrust and fire controls, 5-levels of piay and alien spaceships. 



□ 



DROPOUT" 



£5.95 

Exciting NEW arcade game. Can you destroy the aliens before 
they build up in their atomic plies and overwhelm you. 

Dealers enquires welcome, garteroui ditCOufll*. 

When ordering 2 or more deduct t'l.tX). Send S-A-E tor Catalogue. 
Tick battels) required. 
Cheques/ POs payable lo "SILVER SOFT". 
Name .,,,,.. 



Address 



WA NTE D ZX81. Spectrum. BBC Micro Software 



t^celteoi Rovalil** - S ■ * ■ t . 'in ciiMaili 

All Arcade games, run in 4K 



I 




SINCLAIR USER July 1982 



programs 






\ J -- >J ^ J ^ 


1© 


LET P=0 


ae 


LET Q=P 


30 


LET A* = "" 


40 


FOR C=l TO S0 


50 


LET B*=fi* 


60 


LET f* = INT (RND*3J 


70 


IF P.*0 THEN LET RS="CLUB " 


80 


TF R = l THEN LET R* = b1 BRR 


90 


IF R==2 THEN LET fl* ^'CHERRY" 


100 


LET B*6 


110 


IF INT (C/25 tIKT (C/SJ THEN 


LET 


B«l© 


1S0 


PRINT AT 10.0 J E;fi$ 


130 


FOR Fal TO 30 


140 


NEXT F 


150 


IF Rf<>B* THEN GOTO 200 


160 


LET Ct=INKEYJ 


170 


IF C*=' , 0" THEN LET P^Q + l 


130 


IF CJs^P" THEN LET P=P + 1 


130 


PRINT RT . 3; "*": O .">"; RT 


81; " <"; P; "P" 


200 


IF INKEYIO"" THEN GOTO 200 


210 


NEXT C 



AS ITS NAME suggests. Snap 
is a version of the well- 
known card game but 
instead of cards the program has 
three words, *ctub", *bar* and 
'cherry 1 which appear in random 
order on two sides of the screen. 

When two words are the same, 
the two players have to press their 
keys, either Q or P, as quickly as 
possible, to score a point. 

The game lasts for four attempts, 
and the score for each player is 
displayed at the top of the screen. 

It is a simple game but can be 
fitted into IK RAM and is one of the 
few games of this size which can be 
played by two players. 

Snap was sent by Tim Crossley of 
York. 






SINCLAUtUSER Ju!ylW2 



31 



£^ *££«.■■ the 

A9 the "»™ e '" 0{ numbers 
DbSlB im veto »d pUion .™ a 

score as P 088 '^.. automatically 
The cursor moves a to ^ 

d0W » ^ J^^JdlD the right 
left ueing the ^ SBy 

by the 'M* Itey* - ot time the 

J, Thames, Surrey- 



I 



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nil ^a,'*- ««- ■•"•' kjBl - * 



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a^lSlasJo ... 

111 BSryfc^- T ' - HOUE ™Z 

*£ NEXT J ^ 



OLF 

AbSdeUunhegamaof 
^"outotheZX^endftm 
on6 . se^t b V A Ba-es J .As^ 
under-Lyne. Lancashire, 
!Jersion played on t6K 
memory. * Qm iftr\in.a*nole' 

When th6 t r£ of Ae screen 

screen and the rea ^- ^ ^ eac h 

time, which makes vi gths 

remember angle i ana 
■ r»mprgv^ ssho h 



32 



SINCLAIR USER July Iflffi? 



4AA^ 



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t! Ei Bat 

so let 



«f g ls:-l" WIS Eft &**-« 

Xnn L-E T £ . "HIT 

111 58Sffi B fc?«« "SP- 1 ^ " ? 



B— Twin* i. » l """~ 
pt °fTbu Bg amVLwWch 

a-wamp. „ ma nresaKUN.and 

^^^rshowninona part of 

the fl^amp is snow ran dom 

the screen wi* two ^ugs ^ ^ 

SSS- W^STSSi the 
The game ^* m to earner, 
plus Bign * rom p ^ v T Bb ove5ta8 S o 

Ling the ^f[ a ^ nt 7the *wany. 
that me bugs fall *t the 

Once one of the nus ^ {mB 

game stops and the ieu B 

taken is shovjm wHh the 

same lay out, pressm DreSS RUN. 
youwantanewgame-pr ^ 

The game wa 8 ***J Surrey , 
||T1 ., r, « & vrs of Godaimmg^,^^ 



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SINCLAIR USER July 1982 



en* 811 ' \ScVViav«^ to 
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350 P RJNT . — 

3©0 PRINT * -**-**->- » ta 

393 PRINT -FOP <* -r-c^ 

4.S5 PRINT- "Rnn * 
*^§ JP g~f |H£N GOTO 50* 

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ill KtS-UPw ess? iB * g 

5?S PRTM? CODES; ■■ 
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55© ppirrr 

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gag ?55tff D g NOT ^^R S LID E? y„ N ., 

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S4-0 if bt = "v. *. 

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5C0 PRINT "S-%..-r.*-~ 

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36 



SINCLAIR USER Julyl9fl2 



FROM Daniel Shavick of Mill 
Hill. London, Sheepdog — a dif- 
ficult game which is a good 
representation of a sheepdog trial. 

A aheap, an inverse S. is driven by 
a dog, an inverse D, through a gate, 
denoted by two black squares, and 
into a pen which is shown as a grey 
square. The dog is moved upwards 
by pressing the "0* key, downwards 
by the'.* key. left by 1 and right by 3. 
It continues moving until the S is 
pressed. 

When the dog is within five 
squares of the sheep -, the sheep 
begins to move. The difficulty is that 
the movement of the sheep tends to 
be as wayward as any sheep in a 
real trial. 

After a good deal of 
concentration, the sheep can be 
penned and the time taken is 
displayed. As a guide it took our 
reviewer 1,079 seconds — one 
second short of 18 minutes. 

The game can be re-started by 
pressing NEW LINE. 



10 


PR TNT RT 19,£9;CHR* 136; AT 
CHR* 12S;«T 10,11; CHR* 12B 


10,5; 


20 


LET S=0 


30 


LET A* = "" 


4-0 


LET DH=21 


&& 


LET t>L=5 


60 


LET SH=5 


70 


LET SLss25 


30 


LET Z=S 


90 


PRINT AT SH f 5LiCHR* 164 ; RT 


DH,DL 


.;CHR* 1*9 


102v 


IF 5H=19 ftND 5L=29 THEN GOT 


Q 1002* 


110 


LET S^S+1 


120 


IF INKEY* <>■■■' THEN LET R* = I 


NKCYji 


130 


IF R*=■■ l ■ THEN GOTO 90 

PRINT AT DH.DLiCHR* ; RT SH 


14.0 


, 3L;CHR* 
1^0 PRINT AT 19,29;CHR$ 136 


160 


LET DH=DH+(RS=CHR* 27 RND D 


M < £ 1 ) 


- (R*=CHR* S2 RND DH>0) 


17i«LET DL=E>L+(R$ = CHR$ 31 RND D 
i <3lT- t AS^CHPS 23 AND DL > ) 


ISO 


IF RBS t'SH-OH) >=2 OR FIBS (a 


L-DL! 


>=Z THEN GOTO 90 


190 


IF PBS CDL-5D <Z THEN LET 5 


i_-SL+ (SL>DL* - {SL<DL> 


200 


IF RSS tDH-SH) <Z. THEN LET 6 


H*=SN + (SH>DH> -(SH<DH) 


210 


LET 6H=SH+ (5H < 1) - <SH>20) 


220 


LET SL=5L+f5L<l) -(SL>30> 


230 


IF SH=10 AND (SL<6 OP 5L > 10 


> THEN LET SH=SH~1 


24-0 


GOTO 90 


10B0 


PRINT AT 21,0;S;" SECONDS- 


1910 


PAUSE 4-E4- 


1020 


CLS 


1030 


RUN 




All' 




SINCLAIR USER July 1^2 




WE INCLUDE a special 
program for users of the 
ZX-ao. It is a version of the 
well-known game of Mastermind, 
where four numbers are picked at 
random by the program and the 
plnyer has a Limited number of 
attempts in which to guess the 
numbers. 

To guide the player, the program 
marks each attempt by bulls and 
cows. A bull denotes a correct 
number in the proper position in the 
sequence and a cow means that the 
number is correct but in the wrong 
place. 

The game continues until the 
correct number is guessed or the 
player has had 15 attempts. Press 
RUN for another number to be 
guessed. 

Bulls and Cows was sent by G Gill 
of Westerham. Kent. 



Dfmtt(4] 

FOR A = 1 TO 4 

LETN(A]=RND(9) 

NEXT A 

FOR A - 1 TO 4 

FOR C = 1 TO 4 

IF A-CTHENGOTOlOO 

IF N| A) = NfCJ THEN GOTO 20 

NEXTC 

NEXT A 

LET A = N(l)*lO0O*N|2j 

*10d + N{3)MO+N[4) 

PRINT "ENTEH YOUR GUBSS" 

FOR F = 1 TO 1 5 

INPUT B$ 

IF B$ = "" THEN GOTO S50 

PRINT B$ ;" = "; 

LETB^O 

LET C = 

LET AS = STRIS (A| 

LET X$ = AS 

LET CS = B$ 

FOR S = 1 TO 4 

FOR D = 1 TO 4 

IF CODEfXS) = CODE[CS] THEN 

GO SUB 400 

LETC3 = TU{CS! 

NEXTD 

LET CS = B$ 

LETX$ = TLS(XS) 

NEXT S 

IF B = 4 THEN GOTO 350 

PRINT B: BULLS"; C; "COWS" 

NEXT F 

PRINT "I'LL TELL YOU THAT 

IT WAS"; A 

PRINT" THAT S IT" 

STOP 

IF S = D THEN LET B = B + 1 

IF NOT S s D THEN LET C = C + 1 

RETURN 



• Because of the large number of 
programs which have been sent to 
us, we cannot acknowledge every- 
thing which we receive. If you have 
not heard from us within one month 
of despatch, it is unlikely that we 
will be using your submission. 



3B 



SINCLAIR USER July 1982 




X81 

users 

I need more memory! please rush me the fully 
assembled, tested and guaranteed 

BYG BYTE' 

16K RAM PACK 



Name 



Address 



Make all cheques & PO's payable to:- 
Phoenix Marketing, Oaklands House Solartron Road, 
Farnborough, Hants. Tel: (0252) 514990 



FULLY INCLUSIVE PRICE 

£25.00 



uuT.sr 



PERSONAL SOFTWARE SERVICES 

ESSENTIAL PROGRAMS 

ALL YOU NEED TO SIMPLIFY COMPLEX 

PROGRAMMING 



1/0 ENHANCED BASIC 16k 



£6.95 



4 MUST FOB ALL SERIOUS PROGRAM WRlTEftS ENHANCED BASIC IS STORED 
ABOVE PAMTOP AMD 50 ALLOWS YOU TO OPERATE ON OTHER PROGRAMS. 
SOMEOFITSMANY FEATURES INCLUDE' AUTO RENUMBERING UNO. UDlW Li ALL 
GOTOS * GOSUB'5). BLOCK DELETION OF ANY PART OF A PROGRAM * DISPLAY 
Uf TH E AMOU N T OF M EMORY USED , SAVES HOURS OF TE DIOU S PROGRAMM INC. 



1/1 



IX COMPILER 



16K 



£6.95 



AUTOMATIC A LLY T BANS L.ATES A LARGE SUB SE t OF BASIC INTO M AC H INE CODE 
WHICH IS THEN STORED IN A REM STATf MFNT FOfl USE AS A SUBROUTINE IN 
AN Y PROGRAM Y"OU WRITE. OPERATES ON 35 OF THE MOST VALUABLE SINCLAIR 
flASiC COMMANDS INCLUDING PRINT. CONDITIONALS. POKE. GOTO, GUSUB 
FOB LOOPS ETC ETC. 



1/2 GRAFIX 



16K 



£5,95 



ESSENTIAL FOR THOSE WHO NEED COMPLEX IMAGES IN- THE IR PROGRAMS 
SUPERBLY EA5Y TO USE. WHEN YiJUH DESkGN IS COMPLETE IT CAN EASILY BE 
INCORPORATED INTO OTHER PROGRAMS- IMAGES CAN BE STORED i RECALLED 
AT ANY TIME. REFLECTED [IE MIRROR IMAGE! -MIKED TOliElHEH YOU CAN 
CHANGE THE ■'COLOUR ' . PRODUCE INVERSE VIOED IMAGE SIMPLY THE MUSI 
FLEXIBLE IMAGE PROCESSOR AVAILABLE 



SPECIAL OFFE^H BUY ANY TWO PROGRAMS FOR ONLY Til 50 OR ANY 
THREE FOR CIS 00 

THE ABOVE PROGRAMS ARE ONLY A SMALL SELECTION FROM OUR 
WIDE RANGE OF 2X81 SOFTWARE - ALl OF WHICH 15 AVAILABLE 
THROUGH THE 2X SOFTWARE LIBRARY SAE FOR FULL DETAILS 

cheque or poto pss. i 12 ohv erstfseet. Coventry, eve sfe 



OPENING SHORTLY 

A retailer for Sinclair accessories in the 
Yorkshire/ Lancashire/ Hurnberside area. 

We are situated close to the Ml & M62 
motorways and offering easy parking. 

As well as a complete range of hard and 

software, our service department can 

repair, modify or fit a wide range of 

accessories. 



For further details of these and many other 
services phone: 

PHILIP COPLEY 

on 

0924 272 545 



Manufacturers of accessories looking for a 
retailer in our area are invited to contact us. 

Hours of business: 
MONDAY to SATURDAY, 10am to 8pm 



SINCLAIR USER r u JyJ9«2 



39 






i~.i:rM~.l-rmr.nr,nr,rr,."h,r,r.,nMhr,,,>.rr,nrl.irlhrM.- ! ,nrM.--|.irM:^nFMi,,, ,-.:,,-,! 




mmm 



\ 




= 



Micro Fair and Seminar for all users 
HARDWARE. SOFTWARE. PERIPHERALS. 



UNIVERSITY OF MANCHESTER INSTITUTE OF SCIENCE 

AND TECHNOLOGY. SACKVILLE ST., MANCHESTER 
SATURDAY 24 (10.30 - 21.00), SUNDAY 25 (10.30 - 18001 

JULY 1982 



ID Fp€G <3psw fop MICRO compelse 

2D Club Blends 

30 Bflinf and Guy stall 

40 Ff»ss j&rkioe 

SD Review of Sinclair* Spec! rmj 

ill LeclBpes on 8 mall »fcpc applications 

70 Free Files 8 

SO Gsp and nefteaafnecils 

FD Bless ic cenfps and Piccadilly sialic.! 

100 Free Geffae 

110 Faci lilies ftp ibe Disabled 





§ 



ADMISSION: 



| ADULT 1.00 | 

[ CHILD (under 161 50p | 

{half price with coupon) = 

I Exhibition and other diversions for ZX. BBC, Micro, VIC, TRS. Sharp | 

E Sorcerer. Video Ge n ie. Ta rigerj ne. Nascom , Atari , Pet a nd Ac o r n u se r . i 



THE 

BUFFER 

MICRO SHOP 

(NEXT TO STREATHAM STATION} 

• • * 

NEW SOFTWARE SHOP EXCLUSIVELY FOR 

ZX81 

PROGRAMS. GAMES. ADDONS" 

• * * 

MOST OF THE MAIL ORDER ITEMS ADVERTISED IN 
THIS MAGAZINE AVAILABLE OVER THE COUNTER 

* • • 

LOADING PROBLEMS? TRY OUR INTEFCF ACE 

BUSINESS & TECHNICAL DATA HANDLING PROGS. 

PROPER KEYBOARDS; CONSOLES; VDUS 

* • • 



374A STREATHAM HIGH ROAD, 

LONDON SW16 

Tel: 01- 769 2S87 

S.A.E. APPRECIA TED FOR CA TALOGUE 



—i 



ZX81 & 80 OWNERS 




jn 




EASY TO USE FOR 



ACCESS TO THE OUTSIDE WORLD! 
SPECIALISED PRODUCTS MODULAR 
HOME/INDUSTRY & EDUCATION 

HH9 JNPUT.HZHJTPIJT PORT EiSy Is UK f US flrtwMn It & RAU PACK.fRINTFR nl 
rcQumrfl. No Skill inquired Id cunnec! Lin fie u;efl ftp mc* thi(l|S IS nuilur conLral 
iovnginiuvc tfntftttlt. Mnnwhflfl la pfHilrr5.1lnppy discs,'1i|:Ht n*n i 5.'n-1hpr cgraautcri 
lmipera*ii« mawtan ng vqoanj *Tf if ntrjhmi. crjnlrr}] at naliEinf Mulls rtw Iraei i!ts sic 
Purl hii ] 6 flro srjtnnnablE \!0 lin« and may b* lised «ilhn<it any *l*c|ri>ntj hno*Kdf t Is canntcl 
nlher add gns HoUif board itqui'Ml OHLT »hf>fl two ■ more Mid (ins lie i«Cilini cue tine 
MlflKteW BLEDIir.95 KIT iKMTHOUl CrQEl EH 9b 

UllS * C HAN NIL RELAY HO* To suit pc-1 CmIkI fill nj ?40v AC>) tA 2<UlC or LlOv 
H/3A Up to < unHs i e ]6 relays can twopwibM 1 IH9b 
Pffl l '■■ WAT rqUHSISTDfl DRIVFR E9 95 
liflB I WAT SWITCH UNI1 ilDUCrMUJflALi tL2 Sb 
MSiM i W*!' INOUATOn UNIT (EDUCATIONAL I El? 9b 

MSM IDYSTICK tfHtf OME iZ J OrilWkJ mmr Ik conntdEd yii Nfllhrftraifdi EL!« 
Bltjfl MOTHERBOARD AllorimwItapfccrjfflbinahijiisGllOOflni up In ) 6 IfO lints nuf 
w uwd Lib 95 

PQWFR SUPPLT 6.'7 ir9» DC il 300 mA feautt«a lor use wrhi ia* c-ns TF I ?:U 
tt.9b 



114KJ 

and IS' 



CantKlcltanr (2 30 
EafLNDEDP 10 NOTES FL 



LG MrAlfSINCLiT SJDED EDCECOH El S5 

HIKES IflCLUK VAT 

Rctripis ahrarSprmriiknJ: Dtfcwry Fiormjlly m sr.net AOD WfHr/ufdi [toon |H watts unftri 
£20. »>1h 111* Ctcegllffn oi KMSSOfiet. 14 Ldjc tun f nil initru^ioni inn euntpin •rfli HI 
priKliKts 



"■■"-""■ ■.■■:..,.. J L. ; :M.=L» ; i ;J =. !; . = !J , !;! .: ;!i Li. ; : ! i: 1! iiL.i..i. ll =Ll ! ..l| J UliLllHUIillljUIJllll l H«tH= t m 



munnxiL iiiicTflONiCSK^G 

ini*H|itl VlVL'HOIt.MlUMt 

rn mi inun 



ifttL"E fOH C*T*yooUl 
<«9T»L Oh 1 tLt*HDhS 




40 



SINCLAIR USER fuJy 1 982 




program 
aids 



The popularity of writing in machine code 
is growing. Phil Garrett looks at the 
systems which can help. 

Aids for speed 
and efficiency 



JUDGING by the popularity of 
Space Invader-type arcede 
games for the ZX-fll, and of 
books such as Toni Baker's Mast- 
ering machine code on your ZX-81. it 
seems the ZX-81 owners want not 
only to run machine code programs 
but write them, too. That is scarcely 
surprising, considering the tre- 
mendous speed and efficiency of a 
machine code program compared to 
Basic, but there is a trade-off 
involved. 

I wrote a three-dimensional 
Noughts and Crosses program for 
my ZX-flO which played a good game 
but had a response time of 45 
seconds. A year later I wrote the 
same program in machine code on 
my ZX-fll and Li had a response time 
of less than half a second. Writing 
that program, however, had taken 
eight complete days of my summer 
holiday. 

Broadly speaking, there are three 
types of program available to aid the 
budding machine code adventurer. 
The most complex and prohebly 
most useful programs are the as- 
semblers, which convert 
mnemonics into machine code; then 
there are disassemblers which do 
the reverse and, finally, monitor 
programs which allow close ex- 
amination of a machine code 



program as it runs, plus other 
functions. When Zilog produced the 
Z-BO microprocessor, each of its 
hundreds of instructions was given 
a mnemonic so that users could 
remember what a particular 
instruction would do, For example. 
LD A, H means load the Accumu- 
lator with the contents of the H 
register and represents 124 in 
machine code. The mnemonic is 
entirely arbitrary and could just as 
well have been LOAD A FROM H. 

We could produce a machine 
code program by POKEing instruc- 
tions byte by byte into RAM and 
plenty of machine code loader 
programs do just that. The method, 




program for Basic keywords — LD, 
CALL — and then places the corres- 
ponding instruction in the RAM, 

The ability to use labels makes an 
assembler very powerful, as it 
allows the programmer to refer to 
instruction lines, subroutines, and 
even data by means of symbols, 
rather than having to determine the 
addresses each time. 

Sufficient of Ihe theory; how are 
the ZX-81 assemblers used? Bug- 
Bytes ZXAS assembler is in 5K of 
machine code, with a few lines of 
Basic to operate it. The program re- 
sets RAMTOP automatically and 
loads itself above it. so that 
assembler source programs can be 
loaded and saved separately. Lines 
of mnemonics are entered in REM 
statements, with multiple instruc- 
tions allowed, provided they are 
separated by semi-colons. Up to 255 
labels can be used in the form :L0 to 
:L255, and comments may be placed 
after a * ! * T '. Full-stops are used 
instead of commas — e.g., LD A. H — 
which makes typing instructions 
easier and numbers may be entered 
in decimal or hex. When the 
assembler is run, you are prompted 
for the starting address for the 
resulting machine code. Invariably 1 
use a REM statement at the start of 
the program, and compile the 
machine code from 16514. The 
assembler code is then displayed on 
the screen in the format source line 
number: address (in hex); opcode 
and data [in hex]; Z-80 mnemonic. If 
there is an error, the assembler 



* There is a trade-off between the speed of 
the final program and the time taken to 
write iV 



though, is highly error-prone and 
time-consuming if the program is 
substantial. On the other hand, an 
assembler program converts the 
mnemonic form of instructions — 
which we can understand reason- 
ably easily — into machine code 
which the microprocessor can 
understand and execute. 

In some ways the assembler 
program is similar to the Basic ROM 
in the ZX-81. The ROM scans the 



stops with an error code, so it is not 
difficult to build a syntactically- 
correct source program. 

There is at least one hug in ZXAS; 
the SUB A,n instruction does not 
work but it can be replaced by AND 
A; SBC Aji which does the same. 
ZXAS is a remarkable program and 
is excellent value at £5. 

The only other ZX-81 assembler I 
have encountered is produced by 

continued on page 42 



SINCLAIR USER July 1 9B2 



41 



GOTO 35 




continued from poge 41 

ACS Software. It is similar to ZXAS 
in size and operation, with 
instructions entered in REM 
statements and Labels available in 
the formQ.l: Q.255;, 

Data must be entered in decimal 
rather than hex — I prefer decimal 
— and there is a useful DFB function 
which allows you to specify the 
contents of a particular byte during 
assembly, so you can have messages 
embedded in your machine code. 

The assembled listing display is 
slightly different from ZXAS: you 
are given the decimal address, hex 
opcode and data, and then the 
mnemonic. 

The ACS assembler is also 
excellent value at £5.50 and the use 
of either this program or ZXAS is the 
single biggest step to proficiency in 
machine code programming. 

Neither program sets out to teach 
assembler, so a book will also be 
needed, 1 use the thorough but 
expensive Programming the Z-BO by 
Rodney Zaks but there are now 
several books available specifically 



to the printer and you have to use 
the break key to return to Basic. 
Machine code can be entered, and 
individual bytes changed, using hex. 
This program, price £4, has been 
available since June, 1981 and has 
perhaps been superceded by some 
of the others on the market. 

The Aylesbury ZX Computer Club 
has decided courageously to enter 
the software fray with its 
disassembler. It is a very Large 
program [14K] and runs a Little 
slower than the others. The display, 
which can go to screen, printer, or 
both, is unusual; addresses, 
contents and mnemonic data are 
given in both hex and decimal and 
the display allows one line for each 
byte. There is also a facility to enter 
machine code from address 30000 
in either hex or decimal and an Edit 
function to alter a byte or copy a 
block of bytes from one area of RAM 
to another. It is good value at £$.50 
plus 50 pence for postage and 
packing. 

Bug-Bytes ZXDB disassembler 
can be used in conjunction with its 



'In some ways the assembler program is 
similar to the Basic ROM in the ZX-81/ 



for machine code programming on 
theZX^8l. 

Disassemblers convert machine 
code into mnemonics, making it 
easier to analyse and amend. The 
ACS disassembler can be used at 
the same time as its assembler and 
provides mnemonic listings in the 
same format. All addresses are 
shown in decimal and destination 
addresses are shown for relative 
jumps rather than the 
displacement, which is an excellent 
idea. 

All the other disassemblers have 
additional bells and whistles to 
assist with editing and debugging 
machine code. Campbell Systems 4 K 
disassembler uses plenty of Basic 
and its machine code occupies my 
favourite 16514 onwards area of 
RAM, It has a handy facility to step 
backwards and displays contents in 
hex, with addresses and mnemonics 
in decimal. You cannot dump direct 



ZXAS assembler and occupies 4K 
from address 16514. It works 
entirely in hex and does not dump to 
the printer, although you can 
circumvent that by disassembling 
12 lines or so, then calling 0869H, 
which is the Sinclair ROM COPY 
subroutine. 

Another disadvantage is thai 
some of the mnemonics belong to the 
8080 rather than the Z-flO. e.g., LD 
A. [HL] appears as LD A.M. It has a 
very large number of sophisticated 
monitor functions, so I have 
included it among the monitors as 
well. ZXDB coats £6-50. 

MicroGen Debug is also a 
disassembler with same monitor 
functions, works entirely in hex, and 
can be used with a printer. Care has 
to be taken when transferring from 
Basic to Debug and back, or the 
ZX-81 will crash, I found the monitor 
display impressive, although more 
detailed instructions would have 




been helpful. The program livus 
above RAMTOP. which it re-sets 
automatically, and costs £3.95. 

ACS-Debug can be used in con- 
junction with the ACS assembler 
and disassembler to provide a 
complete, if rather expensive, 
machine code writing package. It 
stores above RAMTOP, uses 
decimal numbers only, and does not 
dump to the printer. Once again, it 
costs £5.50. 

The Picturesque ZX-MC is 
another sophisticated monitor; it is 
rather Like a separate operating 
system. You cannot use it with any 
existing machine code programs, as 
it uses low memory and has its own 
stack in high memory. It has its own 
loading and saving routines which 
operate at twice the speed of the 
ZX-81, The program is complete 
with a comprehensive manual for 
£7.50 but I believe its incompati- 
bility with other programs is a 
serious disadvantage. 

The Taurus Machine Code Moni- 
tor is placed above RAMTOP and is 
available as a cassette and also In 
EPROM form as part of its 16KRAM 
pack system, With the la Iter you can 
switch from 14K RAM plus 2K 
monitor to the full 16K RAM. Apart 
from the usual functions, it has a 
helpful hex calculator and a facility 
to create REM statements of any 
length. It also has a comprehensive 
manual et £7,50 in cassette form, 
and the RAM-pack system costs £48, 

Bug-Byte, 98-100 The Albany, Old Hall Street, 

Liverpool L39EP. 
ACS, 7 Lidgett Crescent, Roundhay, Leeds LS8 
1HN. 
Campbell Systems, 15 Rous Road, Buckhurst 

Hill, Esse* iG9 69L- 
Aylesbury ZX Computer Club, 12 Long Plough, 

Aston Clinton, Aylesbury, Bucks. 
MicroGen, 24 Agar Crescent. Bracknell. 

Berkshire, 
Picturesque, 6 Corkscrew Hill, West Wickham, 

Kent BR4 3B9. 
Taurus, 47 High Street, Eta I dock, Herts 

SG7 6BG, 



42 



SINCLAIR USER July 1982 



THE 



MOf\|Qp3 QLV 



WGAKfOftCc 



\ ' J 



ir^n 



* 

m 



•rgum.ntsl Uh, vfr tu,,lly SSllRSi -1 
comm complete wit* "°"*fc*nd 

an instruction 

bookftC 



« C i>iAY3 waVES 



TRADER JRCR 

Bast d*scribsd as n TRADING ADVENTURE gtnw 
it's a PAIN. Written for MASOCHISTS the gems 
starts INNOCENTLY with £40 r ff» in your hand. THEN 
you're on YOUR OWNI You choose CREW. SHIP. 
STORES and CARGO- You avon choose where to go 
sod atther mak# a FORTUNE or FAIL to SURVIVE. 
GO CAREFUL you nave 200 Byt*a left from 16k 



£5. 95 



140 WILSDEN AVE., LUTON, BEDS. 
Tel: Luton 454456 




The ultimate 

SINCLAIR ZX 81 (16K) 

DATABASE FILING SYSTEM 

by DALE HUBBARD 

Fed up with boring games - make your ZX81 work for youf 
The one you've been waiting fori! 

Cassette based 

FaStieTtndud e P sort!°search, list, delete, change, total numeric field save and load file, line print, etc. 
Complete with demonstration file and full instruction/ application leaflet. 
Requires 16K Ram pack. 
Applications: Recipe file 

Stamp/ coin collections 

Inventory Control 

Employee Data 

Record Collections 

Magazine article catalogue , 

Mav be used for any application where fast access is required to stored information 



Access accepted 

Send cheque or P.O. or credit card number to: 

GEMINI MARKETING LTD. 

Quay House, Quay Road, Newton Abbot, Devon TQ12 2BU 

OR telephone us with your credit card order 
on Newton Abbot (06261 62869 

DESPATCH BY RETURN 



ONLY 

£5.95 FULLY INCLUSIVE 




**& 






KEMPSTON MICRO ELECTRONICS 



PRESENTING 

tH e new 



ZXKLIK- KEYBOARD 



IF VOU ARE like many 2X81 users and are fed up with the 
dead 'touch sensitive' key pad then consider the ad van- 
tages of the new KEMPSTON KLIK-KEYBOARD This is 
a genuine push button keyboard which has been 
designed as an exact replacement, being no larger than 
the existing key pad, but offering all the advantages of a 
full size keyboard, Consider these facts: 

• FitsontotheZXSl, 

• No soldering needed on the assembled version 
{just plug in) 

•Wo trailing wires. 

•No special esse required. 

•Positive feedback from keys. 

•Full two colour legends supplied. 

•Full back-gp service offered, including fitting, 

This is a genuine 40-key, push button keyboard which fits 

into the recess formed after peeling off the existing touch 

sensitive keypad. 

The kit comes with a precision drilled P.CB. finished in 

matt black, 40 keys, 2 colour legends, connecting tails, 

adhesive pads and a full set of instructions, 



Also available from our range of products is a 

Parallel User I/O post €16,50 built & tested Gives 
161/0 lines to drive light relays, motors etc. Many 
already sold to education. Keyboard bleeperCS. 95 
built, repeat key kit C2.95. 




"" Mp*r inrt U«hi 








n™ 












Du« at, 


Pn |H 








zxai K«t«oMd Kit 


at 










2X81 K«vbe*rd AmnnbinJ 


« 


DO 
















■„.,, MM 






tm* 




Hi 


nwt Hllfr* If 4*Yt Inr Jlii>mp 






K«ft*(.«on Micro EI»cTTonL*t 







Proprietor A. Psndaai B.$c„ P.G. Cert. Ed. 



0m 

ZX CHESS & ADVENTURES 

PROGRAMS FOR THE ZXB1/80 INCLUDING - 



MOVING AHEAD 

WITH 

ZX SOFTWARE 



IwfwJzX-FQRTH 
16K RAM PACKS 



1KZX-CHESSII 

ZX CHESS I 
reduced to £6,50 

ZX CHESS II 
rraw only £9,95 

ADVENTURES 

ADVENTURE J A' 

tsm 

ADVENTURE B' 

£7.00 
ADVENTURE 'C 

£8.00 



GALAXIANS 

£3.95 

ZXBUG 
£7.00 

and many mow, For a 



Full implementation of FORTH for the ZX - 1D - 26 
Sme fasts* than BASIC. 'Simplicity of BASIC with 
speed & macliine code. ' 

BYGBYTE RAM PACKS, no wobWe problems. 1 year 
•y uiir an tee nn aa^h RAM PACK , The best yotl can buy . 

Immediate delivery, 

We didn't think it was possible, but the game plays 

■gainst you, two opening moves, only IK of memory 

needed. 

Very popular machine code program, with si* haveis of 

play and an analysis option. Unbeaten except by: 

A new improved version with a faster response lime, 

seven levsts of play, and in addition a recommended 

rfifl we option. 

Exciting machine code games with instant response, 
choose from the range below. You find yoursHt 
stranded on an alien planet. 
Can you reach your ship and escape? 

In a junyle- Clearing you come across an inca temple. 
You must break in, collect treasure and escape alive. 
Beware. Includes a cassette save routine. 
Vqu ere unfortunate enough to be drawn io an alien 
cruiser, Can you reach tbe control room and (Tee 

yourself or will they get you First? 

IndudeS. a cassette save routine. 
All the features ol the acanda game in a fast machine 
code program, Swooping attackers, exptoeions and 
personalised scoring. 

A 30 in 1 machine code tool and disassembler, allows 
access to all registers and to search through, and 
modify memory: with cassette routines. 

catalogue giving full details, please send a S.A.E to 



Artie Computing 

Dept. EE 

396 James Heckitt Avenue 

Hull HU80JA. 




. . . is a stylish and 
ergonomic plinth for the ZX81, It raises and 
tilts the TV to avoid eyestrain, holds the 16KRAM 
in place and hides the wiring and power supply. 
This very professional unit costs £t&, a built-in 
power switch is £3. plus postage at llbo, inc. VAT 

Peter Fur long Product s,125Cat lord Hill, London 5E64PR 
Callers by appointment, please.Tel 01 690 7799. Visa .Access, 



44 



SINCLA1H USER July 1982 



software 
scene 




Accounting for 
small business 



TWO sophisticated ac- 
counting programs have 
been put on to the market 
by Host a crest with the in- 
tention of improving the 
efficiency of routine ac- 
counting at low cost. 

The programs are writ- 
ten for preparing accounts 
from incomplete records 
of a sole trader and a 
limited company. They are 
written for use mainly by 
accountants but they can 
also be useful to the small 
trader with a little 
knowledge of accounting. 

Figures can be entered 
into the accounts in the 
usual forms, including 
cash payments and re- 
ceipts and bank payments 
and receipts, Using a 
system of coding, the ac- 
counts are then built-up 
from those, printing-out all 
the records of interest to 
the company. 

The programs are avail- 
able from HestacreBt, PO 
Box 19, Leigh ton Buzzard, 
Bedfordshire. LU7 ODG. 
costing £17.50 each or £25 
for the two. 

Improved 

Othello 

MINE of Information has 
produced what it claims to 
be an improved version of 
its game Otbello. The im- 
provements include more 
features for a lower total 
price of £6,90, better 
loading and easier use. 

All input is said to he 
crashproof and loading 
problems have been over- 
come by a hardware 
modification to generate a 
strong, clean, original 



signal and tape duplica- 
tion using a signal 
enhancement process. 

The new features in- 
clude the ability to replay 
moves at any stage, both 
forward and backward. 

The new program, 
known as version 3,5. was 
shown at the ZX Microfair 
at the beginning of April 
and lost only one contest 
out of 30 when playing at 
half power, 

Othello is available 
from Mine of Information, 
1 Francis Avenue, St 
Albans, Hertfordshire. 

Adventures 
from Algor 

ALGOR has produced two 
adventure games which 
are different from any- 
thing else on the market. 
She lobs Lair is a 13K 
Basic and machine code 
game which gives a 3D im- 
age of your location and 
shows all the exits in 
perspective. 

There are plenty of 
monsters and treasures, 
represented in words 
rather than graphics, scat- 
tered around the 180 
rooms. 

The room displays are 
generated using code and 
ere impressively fast, The 
layout and the contents of 
the rooms change only if 
you reach a different level, 
in which cese a set of 
tougher monsters and 
more valuable treasures is 
generated. 

The other program is 
Mines and Monsters, 
which allows up to four 



players to play at the same 
time. It is a 13K Basic game 
in which all the locations, 
treasures and monsters 
are generated randomly at 
each turn. 

It is not very exciting but 
is entertaining enough and 
useful, if only to avoid 
family arguments about 
who can use the ZX-81 . 

Both programs cost 
£3.50, Shelob's Lair being 
packaged with an eco- 
nomy simulation game and 
Mines and Monsters hav- 
ing a multi-player stock 
market game. Algor is at 
Dovercourt, St. James 
Road, Northampton. 

Zuckman 
for the ZX-81 

WHAT IS said to be the 
first ZX-81 version of the 
popular arcade game 
Puckman has been produc- 
ed by DJL Software. Called 
Zuckman, it runs on the 
ZX-81 with the 16K RAM 
pack. 

It is very user-friendly, 
giving complete instruc- 
tions for playing. Written 
in machine code, it is a fast 
and interesting game and 
requires a quick apprecia- 
tion of how to move the 
figure. 

Zuckman is available 
from DJL Software, 9 
Tweed CloBe, Swindon, 
Wiltshire. 

Parlez-vous 
le Basic? 

A CASSETTE to help 
children with GCE O level 
French examinations has 
been produced by Rose 
Cassettes, which 

specialises in educational 
software for the ZX-81, 
For use with the 16K RAM 
pack, it covers grammar 




and vocabulary. On the 
first side, there are three 
sections dealing with 
verbs, pronouns and ad- 
jectives, with lessons 
followed by tests. The 
second side deals with 
vocabulary, with 345 
nouns, more than 190 
verbs end about 290 com- 
mon expressions. 

The cassette is 
available from Rose 
Cassettes, 148 Widney 
Lane, Solihull, West 
Midlands at a cost of £4.50 
including postage. 

Fighting the 
Prince aliens 

FOR THE intrepid fighter 
against all things alien. 
Astro-Invaders is the lead 
game in a pack available 
from John Prince Software 
costing £3.65. 

According to the com- 
pany there is no superior 
version of the game on the 
market at such a com- 
petitive price. In machine 
code, it runs automatically 
on loading and involves 54 
manoeuvring aliens which 
are knocked out by photon- 
firing torpedoes. As the 
gams proceeds the attack 
rate increases. 

The other games in the 
pack are Grand-Prix, 
Penalty, Golf and Swat. 

John Prince Software is 
at 29 Brook Avenue. 
Levenshulme. Man* 
cheater. 



SINCLAIR USER Jufyisez 



43 



Micro Gen 



QUALITY PRODUCTS 
ZXS1 A/D CONVERTER BOARD 

This 4 channel analogue to digital converter, originally developed 
forioystick control, can be used for such applications as 
measurement of voltage, temperature, light intensity etc. 
The board fits in between the RAM pack and 1 the ZX8 1 , (Noskitl is 
'squired to make this connection, and u actually improves the 

stability of the ft AM pack), 

Price now only £ T 8- 50 

JOYSTICKS fortheZXSI only f 9.60 each 

" The most exciting add-on ever for the ZX8 1 . free yourself of that 

dead, unresponsive keyboard. 

" 1 or2 joysticks may be connected via our A/D board. 

' Turns your ZX8 1 mto a true programmable games machine. 

* Extends the capability of the ZX8 1 . rmaqme the tremendous 

variety of games and applications thai now become possible 

Details supplied on how to use the joysticks in your own 
programmes 

Please rtote that you cannot connect conventional analogue 
loysticks directly to the digital input ports found on most I/O 

boards, an A/0 converter such as ours is required. 

A free copy of ZX AMAZE plus any one of the games listed below 
when ordering a joystick and an A/D board 

PROGRAMS AVAILABLE 



X SPACE INVADERS 



You've tried the rest, now try the S EST 
This program has many features including an ever increasing rate 
of play fthey'llget you in the end). 

only£3-95 



BREAKOUT 



Quite simply the best breakout on the market. 
Features seven bat angles, f you won' t find this one easy I 

on ty £3.95 



gCTilBffliaaiJ A very addictive arcade game. 

Bomb and shoot your way out of trouble, otherwise you are 

doomed to crash Generates a different pattern, for a different 
game each time you play. On the reverse of the cassette isZX 
REFLEX, find out how fast you really are. 

now only f 395 

I^MBBBI The original and still the best. • Graphic display of 

chessboard * 6 levelsof play. * Displays re cord of your move sand 

ihe computers. * Board can be set up to any position. * Has ability 

to change sides or level in mid-game. " PLUS * CHESS CLOCK on 

reverse side, records time taken by each player. * Resetable 

function. 

* Single key entry 

now only £6.50 



DISASSEMBLER tt MONITOR. 



Allowsyou to enter and run 
yourawn machmf' code Relocates to top of memory to allow you 
lo load oiher programs and find out how they work. Block move. 
Byte search. Loaddisplay and alter all CPU registers. Window on 
m em orv facility, uses standard mnemonics, an absolute necessity 
if learning machine code. 

onlyC3.95 

fcfc*nwiMi T ii ileal This is the fastest arcade type game we know 
32 zones, thrust and altnude controls, smart bomb and firing 
controls. 

only £3 95 



SORCERER S CASTLE 



Adventurs Gar 
options 



New from Micro Gen, Magical 
f- with graphical position Allowing a host of 

£3.9 S 



All ourgamescantae used wrth joysticks or keyboard, (except 
chess and Sorcerer's Castle keyboard only) Supplied on cassette 
with library case. 

It you write a program which is exceptional, please submit it to us. 
We will offer a royalty if it is suitable, 

Cheques + POs: Payable to M IC R OG E N. 2 4 Agar Cres. 

Bracknell, Berks. 

Please arid 40p P& P to all orders 



7X81 THE ULTIMATE 
™* CONVERSION? 

THIS SUBERB LOOKING DESK 

CONSOLE HOUSES A 

ZX81 






n 



If you would like your ZX81 

to look like this, then send it 

to us and we will return if to you built into this cabinet 

including a 9" monitor connected directly to the video output 

of the ZX8I, and a full mechanical key lock. All for £195. 

Alternately we can supply the cabinet only for C3S+ £5 

RIVERSIDE HOUSE, BRADLEV LANE. NEWTON 

ABBOT. DEVON. 

TELEPHONE NEWTON ABBOT {06Z6I 68622. 



MICROWARE 



NEW SHOP IN 

LEICESTER 

FOR 

SINCLAIR 

COMPUTERS 
Keyboards • Ram Packs • 1/0 Parts • 
Monitors • Graphic Boards etc. 
Games, Serious, Home, Business Software, 
Books & Magazines. 

MICROWARE 

131 MELTON ROAD, LEICESTER 
Tel: 0533 681812 

Holiday Closing 

Our shop will only 
be open on Mondays, 
Fridays and Saturdays 
between 28th June and 
16th July 

SUPER SUMMER SALE 

NEW OR GENUINE 

REDUCTIONS' 



Shop Open 

9.30-530 

Closed Thurs, 

S-A.E, Brings 

Catalogue 



MICROWARE 



46 



SINCLAIR USER fuJylSSS 



hardware 
world 




Kempston 
keyboard 



KEMPSTON Electronics 
haa produced a micro- 
miniature version of the 
ZX61 keyboard with real 
keys. It is the same size as 
the original Sinclair 
keyboard and ao can be 
placed on the top of it. It is 
only half-an-inch high end 
its black keys blend well 
with the ZX-81. 

The keyboard can be fit- 
ted by opening the case 
and removing the original 
leads to the sockets on the 
PCS and replacing it with 
the leads from the Kemp- 
ston unit, 

The company also pro- 
duces an Educase which 
e x poses the prin ted c ircuit 
board to the naked eye. for 
students end teachers to 
see through the clear 
plastic cover. 

It is ideal for demon* 
strating the working of a 
computer; the back can 
contain a parallel port 
complete with a demon- 
stration program to run a 
Centronics printer. Unfor- 
tunately there are no 
Sinclair graphics. The 
keyboard costs £22,50, 
Educase £19.95, and the 
parallel port E18.95- 

Kempston Electronics is 
at 60 Adamson Court, 
Hillgrounds Road, Kemp- 
ston, Bedford MK42 6QZ. 

Speech pack 
from DCP 

DCP has produced a 
speech pack which can be 
fitted directly to the back 
of a ZX-fll and which will 
not interfere with any 
planned expansion. Using 
a maximum of two memory- 

SrNCLAlRUSER July 1982 



mapped ports at 49148 
and 49149, the various 
ROMs containing the 
words can be POKEd via 
Basic to the loudspeaker 
included inside the unit. 

The speech can be 
heard through the 
loudspeaker or, if re- 
quired, can be amplified 
via the jack socket provid- 
ed — 8 ohms. The amount 
of words it can say 
depends on the number of 
ROMs fitted inside the 
box. A maximum of four 
can be fitted and the basic 
model is supplied with the 
first one. 



are available at £14.95 
each, including VAT and 
postage, DCP Microdevel- 
opments, 2 Station Close, 
Lingwood, Norwich NR13 
4AX. 

Thurnell 
motherboard 

THURNELL ELECTRONICS 
has now extended its 
range of equipment for the 
ZX-81 to include a mother- 
board, LED indicator 
board, transistor driver 
board, relay board to con- 
trol up to 1.5A AC or 24V 
DC at 3A. All are in cases 
but the original I/O port is 
still available in kit form 
and without a case, 

A motherboard can con- 
nect up to four devices to 
the port at once. The port 
is based on a Zr&OA PIO 




Kempston 's new keyboard. 

Most of the words are 
measurements of one kind 
or another, but PAUSE 
statements between 
words can be altered so 
that you can create your 
own from the words sup- 
plied. You are limited to 
the beginning of words, 
however, as the speech is 
stored only in complete 
words, not sounds. 

The speech pack costs 
E49.95, complete with 
ROM 1. end extra ROMs 



and ao is completely com- 
patible with the ZX-81, It 
costs £14.95 as a kit with- 
out a case and £1 7.95 fully- 
assembled with case. The 
eight-tranBistor driver box 
costs £9.95. and mother- 
board £15.95. For orders 
of less than £20, add 50 
pence for post, 

Thurnell Electronics is 
at 95 Liverpool Road. 
Cadishead, Manchester 
M30 5BG. Tel: 061-775 
4461, 



Printer 
interface 

CAPITAL COMPUTERS 
has produced the first 
motherboard with bank- 
switching incorporated 
on-board. The expansion 
motherboard also sorts 
out the reflections or the 
ROM and RAM so that the 
full 56K left can be used. It 
includes e + 5V regulator 
for a separate power 
supply, an optional metal 
case, and a range of plug- 
in boards. 

The boards contain 16K 
of extra memory, full 
RS232 serial interface to 
drive printers, Centronics 
parallel interface for 
printers complete with 
handshaking, and a 2716 
ROM containing the driver 
routines. 

All the expansion 
motherboard sockets are 
buffered so that the 
puiling-out of cards should 
not crash the system. The 
expansion motherboard 
costs £40,20, seriel/ 
parallel interface board 
£45.95, 16K RAM £33.93, 
and the metal chassis 
£10,50, 

All are obtainable from 
Capital Computers Ltd, 1 
Branch Road, Park Street, 
St. Albans ALl 4RJ. 

Memory board 
from Fuller 

FULLER Micro Systems 
has added a new board to 
its range of equipment 
whch can fit inside its 
keyboard case. It starts as 
an ordinary 16K board 
supplied with the in- 
dustrial standard 4116 
chips but if you decide 
later that you need more 
memory you can upgrade 
the board to a full 64 K by 
changing the RAM chips 

continued on putfo 4B 
47 



*- 






continued /rem page 47 

and a few straps on the 

same board. 

The 16X PCB will fit into 
any motherboard which 
provides sockets for 
boards to plug into and 
costs £39.95. To upgrade it 
to full 64K will cost 
another £45 for instruc- 
tions and the 64K chips to 
fit to the board, 

The complete Fuller 
Micro Systems range can 
be seen and purchased 
from The ZX Computing 
Centre, Sweeting Street. 
Liverpool 2. 

TV Services 
bleeper 

TV SERVICES of Cam- 
bridge has a neat little 
keyboard bleeper called 
the KAT keyboard audio 
tone. The device can be fit* 
ted inside the case in the 
space beneath the key- 
board, or in any other 
place for that matter, as it 
is an extremely flat PCB 
and piezo-electric loud- 
speaker. 

There are only five 
soldering connections to 
make to the ZX-ai PCB. 
as the rest is ready- 
assembled, If that makes 
you nervous, the company 
will fit it to your ZX-81. 

The bleeper gives two 
tones, one when a key is 
pressed and one when the 
computer answers; it also 
signals the start and finish 
of a LOADing or SAVEing 
program. It may also be 
programmed to bleep in a 
program — for simulating 
an explosion — by using e 
PAUSE greater than 5. 

The KAT costs £8.95 if 
you fit it yourself and 
£10.95 if you send your 
ZX-B1 for it to be fitted. 

TV Services of Cam- 
bridge Ltd, Chesterton 



Mill. Frenches Road, Cam- 
bridge CB4 3NP. 

2K monitor 
EPROM 

TAURUS Computer Design 
has a 16K RAM pack 
which also contains a 2K 
monitor EPROM for 
writing machine code pro- 
grams on the ZX-81. It 
replaces the top 2K of 
RAM when the switch is 
thrown on the front of the 



program. All is contained 
in a metal box BVz x 2V4 
x l'/kin. which attaches 
to the ZX-81 edge con- 
nector via a ribbon 
cable to prevent crash- 
ing the program, due 
to the movement of the 
ZX-81. 

The 16K RAM pack 
costs £59.95 with the 
monitor and £49.95 
without, from Taurus Com- 
puter Design, 47 High 
Street, Baldock Herts SG7' 
6BG. Tel: 0462^893900. 




The 16K HAM pock /ram Taurus Computer Desi«n. 



RAM pack and you can 
enter the machine code 
monitor by a simple USH 
command. 

The monitor provides 
facilities such as hex 
arithmetic, break points, 
copying data from one 
place to another, decimal 
to hex conversion, fill, 
memory display, port read 
and write, plus many 
more. The monitor will 
write a suitable-length 
REM statement at the 
beginning of a program, so 
that your machine code 
routine can be stored 
there and will even re-set 
the Basic variables so the t 
a RETURN from the 
monitor will not crash the 



BASICare 
conversion 

BASICare has produced 
the Organic micro, a 
system which makes in- 
compatability between 
systems out-of-date. The 
idea is that every com- 
puter should use the same 
connections to the RAM 
packs and ports but, 
because each time a com- 
puter manufacturer pro- 
duces a new machine it 
changes the way it con- 
nects, that has not been 
possible previously. 

Now BASICare will pro- 
vide a personality module 
to convert the ZX-81, BBC 
computer or Apple in one 



standard connection, so 
that any computer can 
grow from 16K RAM to 
more than 1MB of RAM. 

The packs which use the 
bus will then be available 
to be used by any machine 
to provide printers, ports, 
Toolkit programs. CMOS 
and dynamic modules. 

The silver packs are 
connected mechanically 
as well as electrically, to 
each other, so there should 
be no chance of a faulty 
connection. The basic Per- 
sona module coats £30,42 
inc. VAT and postage. 

BASICare Microsystem 
Ltd, 5 Dry den Court. Lon- 
don SEl 1 4NH. Tel; 01-735 
6408. 



Metrimpex 
disc drive 

METRIMPEX of Hungary 
is introducing a revolu- 
tionary new disc drive 
system to this country and 
at least one manufacturer. 
Macronics, has opted for 
it. The disc drive is very 
similar to an eight-track 
tape recorder, as the disc 
is stored in a hard plastic 
box which is opened only 
when the disc is inserted 
into the drive. 

It can fit in the palm of 
your hand and can provide 
up to 200KB of memory on 
one disc. The power supp- 
ly is + 1 2 V and + 5 V and it 
weighs only 0.47 kilogram- 
mes. 

The drive provides a 
standard interface so that 
it can be used with disc 
controllers already 
available. The price in 
quantity is £50 and detail a 
can be obtained from 
BATS-NCI Ltd, 375b 
Regents Park Road, Lon- 
don N3 IDG, Tel: 01-349 
4511. 



48 



SINCLAIR USER July 1 982 




REGISTER 

brings together the Sinclair ZX world within one cover 



DIRECTORY OF 350 SUPPLIERS 

Schedules of SOFTWAHE programs - 
Games, Educational, Business, Computer 
Enhancement and Domestic sub- divided 
into a further 30 categories. 

Extensive list of HARDWARE items for sale 

Index of ZX PUBLICATIONS 

References to reviews of ZX ware 

USER CLUBS — when and where to meet 



Much other useful information including details of 
other services and programs, notes for new users, 

advertisements. 

Price £2,95 from 
YOUNGS ZX REGISTER 

2 Woodland Way, Gosfield. Holstsad Essex COS 1TH 

The register is being continuously revised and re- issued 
II you want your new product to be in the Register contact us 

We can also arrange for you to oe on PRESTEL 



2X81 ADVENTURE SPECIALISTS 
C2: VOLCANIC DUNGEON/HANGMAN E4.50 
Al VOLCANIC DUNGEON: Rescue it ypu can the Ellin Princess, Mythical 
monsters, pi I*-, ffflrycsverns, diminishing strength 9nd water make your 

quasi anything but easy. 

FULL 16X PROGRAM * # SAVE GAME ROUTINE 

* # SINGLE KEY ENTRY # « 

"Volcanic Dungeon is terrific value and I would raeomnwidl it id 

anyone" Mr > Thomas Cornwall 

B) HANGMAN: Delux version of tha dsssic game. Play against on 

opponent O' the ccwnpu lef ' S 400 word vocabulary . Good graphic*. 

C3: ALIEN INTRUDER/HIEROGLYPHICS £5 00 

A) ALIEN INTRUDER: You awaken to find yew are the only survivor or the 
Explorer Class. 3 Slarship. Can you escape baton you aJso fail wittim to 
tha Alien monstrosity that aavcu red the crew? Th«a are many ways to 
end this HuWenture but only pna way to survive! 

FULL 16K PROGRAM * # INTERACTIVE GRAPHICS 
* *SAVE GAME ROUTINE ** 
Si HElFtOGLYPHlCS: Decode the ancient 39 symbol alphabet m time to 
save the famous ejtplorer, "Wuflie Mafceit" from a sandy grave. 
FULL 16K PROGRAM * #AN I MATED GRAPHIC DISPLAY 
* * RANDOM CODE * * 
C4- WUMPUS ADVENTURE/MOVIE MOGUL £6.00 
At WUMPUS ADVENTURE FOR 1 TO 4 PLAYERS: See* the famous 
creature in the most dangerous, Wurnpvs hunt ever. All the usual 
features are there: 

SUPERBATS *PlTS * TREMORS * SWAMPS *MAGIC ARROWS 
PLUS Exciting new featutes EVIL GOBLINS that wiN try to sacrifice you 

°+ GIANTS ER RENTS « WUMPUS MUCH * MAGIC SPRINGS # 

FULL 16K PROGRAM ft * RANDOM 6 PRESET CAVE PATTERNS 

# #YOU CONTROL THE LEVEL OF DIFFICULTY * * GREAT FUN 

PORYOU AND YOUR FRIENDS ft # 

B) MOVIE MOGUL: Guide your film through the often hilarious traumas of 
production. Use your budejat wisely and you may make e fortune. 
Success depends on many factors and: not just luck. 

FULL 16< PROGRAM * # * 
ORDERS Plui 60p PErP or large S. A. E. for hat to: 

CARNELL SOFTWARE 

4STAUNTON ROAD. SLOUGH, BEHKS SL21NT 

The »bov» n also availao% frnm BUFFER MICHqSHOP. STflEATHAM, LONDON 



Bridge 
* Oortwai*e 




RRM Pack 

ZXSI 



i*«rl. £% 



WOU THE . 



M] 



Buffi HAH/t packs use same neat ABS ptosttc wxe tuniy 1! ■ *i ■ J6iw, 
Supplied with fan™ strip eontwctot ru imutiti/e methama/ st&bt&tn 

t uth niMUntsea futiv lUJ»MJ*Wp n"tr\ ZX Printer f 

Al inclusm* |ii ii vl When rmlEnnif, dtiftuC I T I 1inrn pfite at any ihun (jl •oriwai " 
NOTE Slifc n1 ,ht? B 411 ft AM is uwr* arfHJreiMbie numnn It in 4 attw 

■Mk i) 0k SniLiau BASIC ROM lr«al onlyi 

t^L— _ 6 m Mjchin* code area unafPfldttl by CLEAR. NEW, LOAD, SAVE 

1 * 1F, :WV BASIC program ■**■ 
■■■^^ 'ti 64t BASIC: variables b m**** »] t* iMcMna < odt 

J? qualityjoPtuar. 

SU P t ft iM V A QERS eaiuf ti I1»R AM n.*ed»d I W a* 

Arn-ntwiiLiKlversmnorwiriofi sen-rig [JAL AX* INVAOER5 PROGRAM Now 
mctupcuatES impiiivetl mvadur snaaM. an^nalarj ™ «i8*r» ir>siiuclKjn» i»nii 
leaguit lahfci ul ih* &•■ h>Qhmi scores otlameri ai atcti el 3 h-Hk uSiy Icnita 

CAt-AKT INVAOEHS eass*M» and ir»ifucik>m (minimum ah RAMI 

&iiliauialibl»aiuiiiy {3M 

unvhine todo tur lei culdculiy Hfwi>. JO m*artar» n * <««« m i 

LyNCH HOB ( Family -Fun ho .21 £*»»■"« »nd msti uti iom 1 1*k RAM I t* 34 

A comp«iitivt game lor 3 to 6 fneopiw ThH>ZXijT pk^tturm, k™p» rhr sttxaand 
fynchHS llw losers in urumaied grap+iips,' GnHt fur. Erturmmnal ioc. 



FAMILVFUMNo HH.BAMnn.lv 



I I V, 



Fivp IfmHy Inn ijnmea,. Casse-tlB »nrt Manual iftrtti in1iu£.l«j«4 l*Hnfll. rj*rK)ram 

n " rt5 hl « 

MULTIGRAPHICSZ 3116k RAM n«d«dl , lk ., KS i 

A liHjnrtfy rrwiiu drnrt!" parkauc Of pJ-OCOrtyP mutiny yD« TuBCdntrcHul im £*«■ 

r|..h|ihn.s. 5uM|J j| e f1 •"•'*' ? |J P^O* '"usrraleti m»nLi.t) 
GRAPHICSSIARTtRFACKIFaurlkGTftprilCiffragfjmst E* (* 

C H5«i i h ri i ii i 1 2 pane iIujm raien booitl* i wi Hi HWhw*. M'.'1«i*mi luchnital n«ie» on 

IhBprouram^r^plBin^lneuiKorPLOT.UNPLOT PRINT SPACE AT INKiYS. 

LiU&UB. PFfK H.e Z Stat char juitr 1ables»lt 
STATISTlCSPACKACI;(foiiulkSl«iiaii£*pro9ram*l **» 

i im nn - ."i m B | iau« b* akd i <:»i i u l iniiina*. mairuc nom lor um . tamp* dali 

■ndriNulta CnnipuMr mm SOi iMriane*. nffiaMiun tantfti I m 

Senri I,«* for further drier's.. PrinBi ttimcrusiw 'n Briiiftt Jl** 

luruitetfl CUHlomecS fl*e«S* adri JOp ptN sufrw*™ irerri nu/iawiti fOp 

Overt*** Cuiwners write lur details t>f hafdntra timKin$ t-.ttarifcr 

BRIpr.E SOFTWARE ifiUi 

JtFFRflWUOll MARPIE BRIDGE. STOCKPORT. CHES SKBiHt 

rlinrtriVr hy triinf r~ft* "* fc ™ 1 ■ ■■ ■■'*' f""" 

. r .' rr/ff etirjtjitwi wiriftHfiet} 




EDUCATIONAL COMPUTING 

on the 




X81 



A" pfogrffrrimei 
til 1K 

Grmmtiv us* at 
grtpNcs 

Ms/iy irtnovaiii/e 

Fu/ry documented 

Includes many 
games 



A Mt of p n tgrm m mtt lo rum 
SkKlm* ZXttr into m r»«»bl tduejuronaJ 
And kw <taJrl •*■** "•» d '* *'»*' J»roBf*«im(nj| 
Tnw« ar* dear injrrucliovii •no' pfanrjr or rip* 
1 rdixt* &»*J^»p' *o 0O.I>*)Wn)flr cFfiJJ # p/*CfiC* 
ft,* momotm tmmnm? ttreu&i i™**l»* * <**c«»)i ] 

lfichjd*s 

roftroJSE 

A sirnulilifld 
version of the 
famous Turtle 
programme 
COPED MISSILE 
Combines the 
tun of ttrt.arle 
games vvith 
iesr nmg 





£4.95 only 

mcl p Rr P 

Gidpn-ptutier • Histotjram # Simon- spell • Sktu-hUjtfd • Times -unit • Set] 
Senes-quil • Kt noorrJirialBS • Count • Equalmns • Artas • Gu«s- a-Vohirc 
Angles • Upstairs -Downstairs • Mutt- notes • Stoat* • W'pp -out •Spell 
lemrjirature • Clatk • Money • Snakr 
Mastermind V Number shoot • +26 more 

n: — 

IEDUCARi; [| endose ctieque pejst.il order for £ 
London ! Address I 

I L-___^^^^ -J 

L*f (to *™M bfnr'il *»fly 6*nd n*«* 



JDUCARE 

| PlnM send me <.upiti Edun>'e-» iO | 



SINCLALRUSER July 1982 



4'i 






ZX81 SOFTWARE 



ALTERNATE PROGRAMS H-1BKI 
FOB THE MORE DISCERNING ENTHUSIAST* 
C*SS£1 T t 1 

MATHS ONE lit*) 

• , i. Oh. Ai l PAR IH 1 S ' Pi .MnirlKl tr, in •niche in Pr»£ i* gl CoTilKJllllf IJjn 9 1 J en 
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mom lhan El» luymg r pl v M rnf lrtHj iH wrong [r, j^awi' ' MA TH5CHC Will giK« HWF 

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nvjno. H«]lin:h«*ha**tuit,iBo»int«d<]nihB i er i | H(Utl is m» child™ II.. «ilp.pen 

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MAIHSKATFllHd 

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LANGUAGE THAAjSLATOft 

h*vi"SI dUf-c ulm mil lorrian ICKi ! Tin* I'm <i sh* program Mr m*i> Fjm wtug top *ara 

IrjnilHlID*! ham fiO0 MinH in lettundft WltfBlm CM HM*>S be chdnfMl otiH SAVED on 

1'iEii" Please lurielarifrij^wr h«m:e 

WDflO TEST 

far lha mn, njnwr mombufi ol in. limn, VYOSD Jfsr Mill givr rhiifren pjHiull, 
cumpuraa »„jirjj second Hm, «» **i*ei1 *iu (Me m» aui nl inn mtfi [mutt 

anj'rter* BFB fhDtfin 

L*nijuBBpTrB*iilaiQr . ttvrfTffdri £3Jf 

CASSETTE 3 

6iNH*CC0JNT |1B*.I 

lAmv man lv l niltwiil mhen you can. «ia« vrhir n>n perianal bjrtLinu Tyiiem 1 

*■■ I'l.l-- !l*-id."a [Kdoft ii. in r u,n.,iy, H ind ** mil rlw w n*|. ^ur bjIs.n'.H n, below 

HH rnH hnniing nn-,,r rrn-n imtl> chare* you lor HI Js.*i MM (he bank' S I jr»ni r „i, Hn 

ill rii: lii*t«jinfl 1I piDl'SO irarmnnicnn nn b« armad" 

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rOUB OHCEH IS SE-CEIVtD 4T6J JO AMD JS DESPATCHED iYli^O THE <iAyf 
OAT U DAV MONEY HACK O ijARANTEE W NOT S* TISFlLO . 11 MGNTH 
R£ ^LAC LWE N T G IjAHANTt £ 



FUTURESOFT 

38 PENSHURST ESTATE, PRINCE OF WALES ROAD, 

LONDON, 1M.W 5 



fflmm 




zxai 

EXU 

lK.\ntt 
Uf i/(i GESti 



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MiTU> in mhuh i«u pi*, ih, p in „r > hoipftaill M*nai K rr lopinij wisii ii., 
pri-frlrlris und dKl^im iainKrd in running ,,, u , r | tt h.lKrrr ifi «i rriaiM 

lahirrs ii is ifniHi^ibi. si ihnn he f r b U( iwiudnl „rr l„rm f r„p 

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plHN IE rur lilrniJIi Imurs un end me hmi- prifiii!). 

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mxtr pevitbi* to. 4l»w un GAMES 
m; I>*fi< v.i. ftft fltf-.t J» 





TRADER 



It is hard enough to look at an amorphous 
hydrosilicon blob from Psi, never mind swing a deal 
with one. But when they ask to pick your brains, do 
you really know what they have in mind . . . ? 

'Trader' is a new concept in ZX81 games. It is a graphic 
adventure so big that it fids your 16K Ram three times. 
You are an in terga lactic trader and the life is tough, the 
bargaining hard. You can make a fortune or end up spaced 
out in a Deltan hellhole. 

'Trader'. 48K of adventure that will run in your 16K Ram. 
It costs El 0,50 inclusive. Send S AE for more details of 
Pixel games. 

PIXEL 

Pixel Productions 39 Ripley Gdnv London SW14SHF 




Professional Grade Keyboard 
and Case at Unbeatable prices 

*Qur case takes the ZX-81 printed board 
* Keyboard supplied fitted to cast 
*Your Ram Pack plugs into rear of case 
*Assembled Keyboard and case price £36,0(1 
■^Keyboard [complete with ribbon cable & connectors 
*tVo soldering required 

*Lar W e keys are used with changeable keynwkers 
^Key board ready assembled prire £24.00 

•Sinclair makes the best home computers 

and we make the beat keyboards » 

*Ftdl mom*/ bark guarantee if you tsrr nut fttih saiutfird 

'Prices tmiofir VAT' 

*16K Ram Pack - fuDy tested, ready built and in a case. 

Uses existing power supply, *STAR BUY £28,00 * 

Mail Order Address: PS^seaddll 5&P&P 

<i< >H l>OX ELECTRONICS Mahrct^^kto 

7 1> M i>un that t ei i Huad , GQf&XM f;/JJt TWaVKS 

Bra in tree, Ksscx CM 7 fiTP. Telephone jt>:i76 r 2BtHK. 



SINCLAIR USER July 19fi2 



50 



THE EXPLORERS GUIDE 
To The ZX81 

The Book for the ZX81 Enthusiast, 

By Mike Lord, 120 pages. 

Programs for IK RAM, and programs for 

16K RAM. Games, Business and Engineering 

Applications. RAM 8 I/O Circuits. Useful 

ROM Routines, Hints and Tips. 

£4.95 



What Can I Do with 1K? 

By Fi.iHjflf Valentine A. 'rash and original book containing 4& programs arid < uu [in«™ lor 
tne unenpanded ZX81. 



The ZX80 Magic Book 

■Wi-'-. flK ROM/ZX61 Supplsnwvt* 



U ffi 



Mastering Machine Code on your ZX81 



By Torn BaHvr IBP p*9= of immftm v«lu» la twQjnrw and super i alike. 



- J K 




ALL PRICES tMCLUQE U.K. P & P AND 
IS* VAT WHERE APPLICABLE 
OVERSEAS CUSTOMERS ADO (1 5G 
CARRIAGE PEA OFDEfl 
PAYMENT WITH ORDER PLEASE 



TlMEDATA LTD ttapl H. SJ Swdowdlile. Bai*ld»ri 
Ew*i SS16 5JG T*l loam 41 1 1ZS (MOM FHIi 



ENHANCE YOUR SINCLAIR ZX8V. 

Video Inverter adds 
professional touch 

Displays sharp, white characters on solid black 
background TV screen. 

A toggle switch lets your choose between NORMAL 
and REVERSE. 



NEW 
ORDER NOW! 



ONLY £5 

(VAT, P&P incl.) 



A small printed circuit board fits on top of the logic 
chip inside your ZX81 , 

Comprehensive, easy to follow, step by step 
instructions make the modification a simple task. 

For convenience print your name and address on back 
of your cheque Or postal order and Send to: 

D. FR/TSCH, 

6 Stanton Road, 

Thefwaii, 

Warrington 

WA42HS 



SOUNDwithZX-81! 



MAKE AMAZING SOUND EFFECTS WITH 
YOURZX-81 



«* 




fr> 



hMh £25.95 THEZONX-81 

■^7% ir<Clp&p&VAT 



f 



rrf 



V 



* The ZQH X as SOUND unit is compieieiy ieiF-commnsd and 
especially desigded for us&wrth rneZX-fli "jusi plugs in - 
no gjsrngnTlnrrg or soldering 

* No power pack, Potteries leads or o"n»r enrras 

# Manual volume Con fro I on po n*( - ample yoIu me Irom duiim n 

# Standard ZX-fll - 16K fccmpacfc or primer con tie plugged mta 
ZON i-81 Sound. Unri without off string normal ZX 4 1 Operation 

* Huge range or possipie sounds tai gomes or Music 
Helicopter*;. Sci-F i Space Invaders, Explosions Gun-shots 
Drums Planes Losers Organs. Bells. Tgnes. Chords etc or 
uvnalever you devise' 

• Uses 3-chanrel sou nd chip giving prog ro rrnne coftlral of p ire h 
volume of rones and ncus-e oil with envelope control 

• E osrly added lo exiling gomes or progromdies using a few 
simple BASIC lines 

FULL insir uc1 ions with many exani pies at how lo obtoi n eTf eels o nd ttie 
programmes, supplied Fully Guaranteed 




ZX81 PERSONAL BANKING SYSTEM 
with load/save datafiles at double speed 

Load the program in the normal way — enter, amend or delete your 

transactions (ZX81 wilt automatically scan standing order File and post 
any items due) — jiave the file of data onto cassette in 45 seconds — load 
a different daLafile into the same program, also in 45 seconds — enter 
items, etc, — save datafile only onto cassette. (45 seconds) — repeat 
operation tor any number of accounts. 

Absolutely no need to save pmgram. as all information is held in 
datafiles. Very easy to use — unlike other bank accounts. Requires a 
minimum of 16K RAM can use much more (no modification required)'. 
On Demonstration at the next ZX Micro Fair. 
The Personal Banking System also includes the following features: 
Full page detailed Bank Account, dual display tor printout). 
Automatic generation of standing orders on due dates. 
Validation of all entries. 
Correct any item previously entered. (Single/Multiple Field 

correction.) 
Enter an item (previously omitted I in the correct date order of the 

account. 
Single key operation. Utilises a M/C keyboard scan. 
Search for anv item or items by cheque' number, description or 

amount — display (and printout if required} with totals. 
Continuous display of statement extract, continually updated 
during input of entry. 
File of standing order details can be displayed, printed, added to,. 

cancelled and amended . 
Detailed User Manual. 
After sales maintenance. 

Send £9.95 ($20) incl. for cassette and users manual to J. P. 
Gibbons A.LB. r 14 Avabn Road, Orpington. Kent BR6 9AX, 
England. (Send large S,A,E. for details J 

There are only two suppliers of supported ZX81 software, this is 
one of them, Be sure to include your name and address, 

Cuming «uon: Bank Reconciliation Module — a separate 
program on cassette that utilises data supplied by 
the main program (S.A.L. for full details). 
The only expandable system for the ZXB 1 
The Personal Banking System is also available from the Buffer 
Shop. Streatham. London and Branches of the Computer Bookshop 
(.roup, full maintenance still available. 



SINCLAIR USER July 1982 



31 




Two of the leading figures in the development of the Spectrum, 
Richard Altwasser and Steven Vickers, have cut their links 
with Sinclair and set up their own company 



Secret plans laid 
by new company 



TWO OF the leading figures in 
the development of the ZX 
Spectrum have cut their links 
with Sinclair Research to set up 
their own company. 

Richard Altwasser, who designed 
the hardware, and Steven Vickers, 
who wrote the programs for the 
ROM working memory, heve formed 
Rainbow Computing Co. Apart from 
publishing a book of programs for 
the Spectrum, the company plans 
are a closely -guarded secret. 

"It is necessary for us to be very 
cagey and apart from the one thing 
which we have announced, we 
would like to leave anything we are 
doing secret until it is ready for 
launching," says Altwasser. He 
adds, however, that something will 
be announced before the end of the 
year. 
They decided to make the move 



they had also been tempted by the 
money Give Sinclair was making, 

Altwasser 25, gained a degree in 
engineering at Trinity College, Cam- 
bridge and went to work for a micro- 
based automation company in 
Worcester but found the organise- 
tion too limiting. After 16 months he 
Left and joined Sinclair Research in 
September, 1980. 

He did some work on the develop- 
ment of the ZX-81 and after its 
Launch in 1981 he was made res- 
ponsible for computer research, 
which involved him in the design of 
the hardware of the Spectrum. 

Altwasser has also been writing 
software for the ZX-8 1 and his 'Cam- 
bridge Collection' has sold 30,000 
copies. 

Before joining Sinclair he had a 
little knowledge of computing, own- 
ing a TRS-flO and having run a 



'We had plenty of freedom working at 
Sinclair but at the end of the day if a 
decision needed to be made there was one 
man who took that decision' 



now beceuse their ma|or project for 
the last nine months, the Spectrum, 
had ended and, like many other peo- 
ple, they wanted to be their own 
bosses. 

"We had plenty of freedom work- 
ing at Sinclair but at the end of the 
day the company was run by one 
man and if a decision needed to be 
made, there was one man who took 
that decision," Altwasser says. 

He and Vickers add, jokingly, that 



course in teaching Basic. 

Vickers' knowledge, however, 
was much less. "Two years ago I did 
not even know what a ROM was." he 
says. 

Vickers, 29, was also at Cam- 
bridge, gaining a degree in 
mathematics at King's College 
before doing his PhD at Leeds. In 
1980, after writing to a number of 
computer companies, including 
Sinclair, for a job, he joined Nine 



Tiles, a software consultancy based 
near Cambridge, which had written 
the ROM working memory for the 
ZX-81. 

His first job was the adaptation of 
4K ZX-80 ROM to make an 8K ROM 
for the ZX-81. He also wrote the 
manual for the ZX-8 1 and went on to 
write most of the ROM for the Spec- 
trum, as well as assisting with the 
manual. 

Both say that they found working 
for Sinclair very exciting — "pro- 
viding you can cope with the 
pressure without having a heart 
attack," The main difference they 
found between Sinclair Research 
and other companies in electronics 
was that "deadlines were vary real 
deadlines '. Vickers says: 

"There is a definition of a 
deadline; that it is the date before 
which something should not be com- 
pleted but that is not the case with 
Sinclair." 

Development of the Spectrum was 
typical of the way in which Sinclair 
Research works. A rough specifica- 
tion was worked-out with the main 
requirements, including colour, 
high-resolution graphics and im- 
proved tape storage interface. 

That was set last September with 
a final deadline of the Earl's Court 
Computer Show in April. By that 
time the Spectrum had to be ready to 
go into production, which meant 
that not only had all the develop- 
ment work to be done at Sinclair 
Research but also all the suppliers 
had to be chosen and the production 
lines at Timex had to be tooled-up. 

That had to be done in conditions 
of great secrecy and very little infor- 



52 



SINCLAIR USER July 1982 




Steven Vj titers {left} and flichard Altwasser { 

mation leaked-ouf about the 
machine, although Altwasser says 
he was surprised by how much was 
known about it before the launch. 

In the end, with many nights of 
working late, the deadline was met 
and the Spectrum launched on time. 

Other benefits of working for 
Sinclair were that there was no 
shortage of money for research and, 
as it was a small company, it was 
easy to obtain quick decisions on 
new ideas and new ways of doing 
things. 

"When I went for interview I 
asked about money being available 
if a piece of equipment was needed 
and was told that a request was 
never refused, but that they might 



right) in front af Trinity College, Cambridge. 

advise about something which 
would be better," say Altwasser, 

For the future, Vickers and 
Altwasser say they are concerned 
to prevent a Japanese invasion of 
the British market. Their plans for 
doing that, however, are to remain 
secret. 

Asked if their name denoted any 
link with the Spectrum, Altwasser 
replies that the only connection was 
that it has been one of the sugges- 
tions for the new machine which 
they had liked, so had decided to use 
it. 

One of their major concerns is 
that they s hould be ab le t o keep pac e 
with the latest developments in their 
field. 



"Tnere will always be the fear 
that something you have designed 
will be out-of-date as soon as you 
have finished it," he says. 

They also think that the present 
generation of computer tech- 
nologists will find increased 
pressure from today's school- 
children, Altwasser says that 
teenagers are now able to grasp 
ideas with which he had difficulty 
less than three years ago. 

He adds that at the Earls Court 
Computer Fair he saw some 
children with leaflets about the 
Spectrum, As a joke he decided 
to ask them about it and was 
told enthusiastically about its 
capabilities. 



SINCLAIR USER inly 1962 



S3 



New ZX8I Software 
from Sinclair. 



A whole new range of software for 
the Sinclair ZX81 Personal Computer 
is now available - direct from Sinclair. 
Produced by ICL and Psion, these 
really excellent cassettes cover 
games, education, and business/ 
household management. 

Some of the more elaborate pro- 
grams can only be run on a ZX81 
augmented by the ZX 16K RAM pack. 
(The description of each cassette 
makes it clear what hardware is 
required.) The RAM pack provides 16- 
times more memory in one complete 
module, and simply plugs into the rear 
of a ZX81 A n d th e price has j ust bee n 
dramatically reduced to only £29,95 

The Sinclair ZX Printer offer full 
alphanumerics and highly-sophisticated 
graphics. A special feature is COPY 
which prints out exactly what is on the 
whole TV screen without the need for 
further instructions. So now you can 
print out your results for a permanent 
record. The ZX Printer plugs into the 
rear of your ZX81 . and you can 
connect a RAM pack as well. 

Games 

Cassette 01: Super Programs 1 (ICL) 

Hardware required - ZX81, 

Price - £4.95. 

Programs - Invasion from Jupiter. 

Skittles Magic Square. Doodle. Kim. 

Liquid Capacity, 

Description - Five games programs 

ptus easy conversion between pints/ 

gallons and litres 

Cassette G2 : Super Programs 2 (ICL) 
Hardware required - ZX81 
Price - £4.95. 

Programs - Rings around Saturn. 
Secret Code MindbogglJng. Silhouette. 
Memory Test. Metric conversion. 
Description - Five games plus easy 
conversion between inches/feet/yards 
and centimetres /metres. 

Cassette G3: Super Programs 3 (ICL) 
Hardware required - ZXB1. 
Price - £4 95. 

Programs - Train Race. Challenge 
Secret Message. Mind that Meteor. 
Character Doodle Currency Conversion. 
Description ~ Fives games plus currency 
conversion at will - for example, 
dollars to pounds 

Cassette G4: Super Programs 4 (ICL) 
Hardware required - ZX81. 
Price - £4.95. 

Programs -Down Under. Submarines. 
Doodling with Graphics. The Invisible 
invader Reaction, Petrol. 
Description - Five games plus easy 
conversion between miles per gallon 
and European fuef consumption figures 



Cassette G5: Super Programs 5 (ICL) 

Hardware required - ZX81 + 16K RAM. 

Price - £4,95. 

Programs - Martian Knock Out. 

Graffiti Find the Mate. 

Labyrinth. Drop a Brick. 

Continental. 

Description - Five 

games plus easy 

conversion 

between English and 

continental dress sizes. 



16K RAM 



Cassette G6: 

Super Programs 6 (ICL) 
Hardware required - ZX81 
Price - £4.95, 

Programs - Galactic Invasion, Journey 
into Danger. Create Nine Hole Go ft 
So I it aire. Daylight Robbery. 
Description - Six games making full use 
of the ZX81 's moving g raph i cs capabil i ty. 

Cassette 07; Super Programs 7 (ICL} 

Hardware required - ZX81 

Prtce; - £4.95. 

Programs - Racetrack. Chase. NIM. 

Tower of Hanoi. Decking the Spaceship 

Golf. 

Description - Six games including the 

fascinating Tower of Hanoi problem. 

Cassette G8: Super Programs 6 (ICL) 

Hardware required - ZXS1 + 16K RAM. 

Price - £4 95 

Programs - Star Trail (plus blank tape on 

side 2). 

Description - Can you, as Captain 

Church of the UK spaceship Endeavour, 

rid the galaxy of the Kfingon menace? 

Cassette G9; Biorhythms (ICL} 

Hardware required - ZX81 + 16K RAM. 

Price - £6.95. 

Programs - What are Biorhythrns? 

Your Bio hythms 

Description - When will you be at your 

peak {and trough) physically, 

emotionally, and intellectually? 

Cassette G10: Backgammon (Psion) 
Hardware required - ZX81 + 16K RAM 
Price - £5,95, 
Programs - Backgammon Dice. 

Description - A great program, using 
fast and efficient machine code, with 
graphics board, rolling dice, and dou b- 
ling dice The dice program can be 
used for any dice game. 

Cassette G11: Chess (Psion) 
Hardware required - ZX81 + 16K RAM. 
Price - £6.95. 

Programs - Chess. Chess Clock. 
Description - Fast, efficient machine 
code, a graphic display of the board and 
pieces, plus six levels of ability, combine 
to make this one of the best chess pro- 
grams available. The Chess Clock 
program can be used at any time. 




Cassette G12: 
Fantasy Games (Psion) 
Hardware required - ZX81 (or ZX80 
with 8K BASIC ROM) + 16K RAM 

Price - £4.75. 

Programs - Perilous Swamp Sorcerers 

Island. 

Description - Perilous Swamp rescue 

a beautiful princess from the evil wizard 

Sorcerer's Island: you're marooned To 

escape, you'll probably need the help 

of the Grand Sorcerer 

Cassette G13: 

Space Raiders and Bomber (Psion) 

Hardware required - ZX81 4- 16K RAM 

Price - £3.95. 

Programs - Space Raiders Bomber 

Description - Space Raiders is the ZX81 

version of the popular pub game 

Bomber: destroy a city before you hit a 

sky-scraper. 

Cassette G14: Right Simulation (Pskw) 

Hardware required - ZX01 + 16K R AM. 

Price -£595. 

Program - Flight Simulation (plus blank 

tape on side 2) 

Description - Simulates a highly 

manoeuvrable light aircraft with full 

controls, instrumentation, a view through 

the cockpit window, and navigational 

aids. Happy landings! 

Education 

Cassette E1 : Fun to Learn series - 
English Literature 1 (ICL) 
Hardware required - ZX81 + 16K RAM 
Price - £6 95, 

Programs -Novelists Authors 
Description - Who wrote 'Robfnson 
Crusoe'? Which novelist do you 
associate with Father Brown? 

Cassette E2: Fun to Learn series - 

English Literature 2 (ICL) 

Hardware required - ZX81 + 16K RAM 

Price - £6.95. 

Programs - Poets, Playwrights Modern 

Authors, 

Description - Who wrote Song of the 

Shirt? Which playwright also played 

cricket for England? 




Cassette E3: Fun to Learn 
series - Geography 1 (ICL) 
Hardware required - ZXS1 + 
16KRAM. 
Price - £6.95. 
Programs - Towns in England and 
Wales Countries and Capitals of Europe. 
Description - The computer shows you 
a map and a list of towns. You locate 
the towns correctly. Or the computer 
challenges you to name a pinpointed 
location. 

Cassette E4 : Fun to Learn series - 

History 1 (ICL) 

Hardware required - ZX81 + 16K RAM 

Wee - £6.95 

Programs - Events in British History. 
British Monarchs. 

Description - From 1066 to 1981, find 
out when important events occurred. 
Recognise monarchs in an identity 
parade- 
Cassette E5: Fun to Learn series - 
Mathematical (ICL) 
Hardware required - ZX81 + 16K RAM. 
Price - £6.95. 

Programs - Addition /Subtract ion. 
Multiplication/Division. 
Description - Questions and answers 
on basic mathematics at different 
levels of difficulty. 

Cassette E6 : Fun to Learn series - 
Music 1 (ICL) 

Hardware required - ZXS1 + 16K RAM. 
Price - £6.95. 

Programs - Composers. Musicians- 
Description - Which instrument does 
James Gaiway play? Who composed 
'Peter Grimes'? 

Cassette E7: Fun to Learn series - 

Inventions 1 (ICL) 

Hardware required - ZX81 + 16K RAM 

Price - £6.95. 

Programs - Inventions before 1850. 

Inve n tion s s in c e 1 850. ' 

Description - Who invented television? 

What was the dangerous Lucifer? 

Cassette E8: Fun to Learn series - 

Spelling 1 ((CL) 

Hardware required - ZX81 + 16K RAM. 

Price - £6.95. 

Programs - Sen es A1 - A1 5. Series B1 -B1 5. 

Description - Listen to the word spoken 

on your tape recorder, then spell it out 

onyourZXSl 300 words in total 

suitable for 6-11 year olds. 



Busmess/household 

Cassette B1 : The Collector's Pack (ICL) 

Hardware required - ZX81 + 16K RAM. 
Price - £9.95. 

Program - Collector's Pack, plus blank 
tape or s ide 2 f o r p ro g ra m /data sto rage 
Description - This comprehensive pro- 
gram should allow collectors (of stamps, 
coins etc) to hold up to 400 records of 
up to 6 different items on one cassette, 
Keep your records up to date and 
sorted into order- 
Cassette 52: The Club Record 
Controller (ICL) 

Hardware required - ZX81 + 16K RAM. 
Price - £9.95. 

Program - Club Record Controller pi us 
blank tape on side 2 for program/data 
storage, 

Description - Enables clubs to hold 
records of up to 100 members on one 
cassette. Allows for names, addresses, 
phone numbers plus five lots of 
additional information - eg type of 
membership. 



Cassette B3: VU-CALC (Psion) 
Hardware required - ZX81 + 16K RAM. 
Price - £7.95. 
Program - VU-CALC, 
Description - Turns your ZX81 into an 
immensely powerful analysis chart. 
VU-CALC constructs, generates and 
calculates large tables for applications 
such as financial analysis, budget 
sheets, and projections. Complete with 
full instructions. 

Cassette B4; VU-F1LE (Psion) 
Hardware required - ZX81 + 16K RAM. 
Price - £7.95. 

Programs - VU-FILE, Examples. 
Description ~ A genera I -purpose infor- 
mation storage and retrieval program 
with emphasis on user-friendliness and 
visual display, Use it to catalogue your 
collection, maintain records or club 
memberships, keep track of your 
accounts, or as a telephone directory. 

How to order 

Simply use the FREEPOST order 
form below and either enclose a 
cheque or give us your credit card 
number Credit card holders can order 
by phone - simply call Camberley 
(0276) 66104 or 21282 during office 
hours. Eit her way, please allow up to 
28 days for delivery, and there's a 
14-day money-back option, of course 




ZX8I 
SOFTWARE 

Sinclair Research Ltd, 

Stanhope Road, Camberley, Surrey, 

GUIS 3PS. 

Tel: Camberley (0276) 66104 & 21282, 



To: Sinclair Research, FREEPOST, Camberley, Surrey, GU153BR 
Please send me the items I have indicated below, 



Oty 


Cassette 


Cede 


Item 

price 


Total 




G1 Super Prog<arriS 1 


30 


£4 95 






G 2 Super Programs 2 


31 


£4.95 






G3: Super Programs 3 


32 


E4 96 






G4: Super Programs 4 


33 


t 4 95 






G5: Super Programs 5 


34 


1 4 9$ 






<36: Super Programs 6 


Ah 


£4.95 






£37'; Super Programs 7 


30 


£4.95 






SB: Super Programs 8 


37 


£4.95 






G9 Biorhythms 


38 


£6.95 






hiacfcgammgn 


39 


£5.95 






(,■ i crwM 


40 


£6.95 






Ql3. Fantasy Games 


41 


£4.75 






013 Space Raiders & Bomber 


42 


£3 95 






Q14 FJighl Simulalion 


43 


E&8C 






El English Literature t 


4-. 


,.;■!', 





air 


Cassette 


O* 


price 


TofiH 




E2: Ertalrsfi Uteralur* 2 


4-, 


MM 






E3: Geography < 


46 


£6 95 






E4: Hislory l 


47 


case 






E5. Malfiernatics I 


48 


£E8G 






E6 Music 1 


49 


£6.95 






E7: inverHrorBl 


SO 


COM 






EB 5pdllir»3l 


51 


case 






B1 CotoctorePac* 


92 


BOSS 






82; ChJb Record Controller 


53 


£9 95 






B3: VU-CALC 


54 


£7 95 






B4: VU-FILE 


55 


£795 






ZX16K RAM pack 


IB 


£28.01 






ZX Ptintot 


27 


i.-* ■■■>'-. 






Fasti packing - 

only rf ordenng hardware 




£2.95 





TOTAL t 



I enclose a cheque/postal order to Sinclair Research Ltd for £. 

Please charge my 'Access/BarclaycaroVTrustcard no. 



*Piease delete as applicable. 


1 1 1 


1 1 1 1 


J 1 1 1 1 


I Mr/ Mrs /Miss III III 


1 1 1 


1 1 1 t 1 1 1 1 1 


Address 1 1 1 1 1 1 1 1 1 1 


1 1 1 


1 1 1 1 1 I 1 1 1 


1 1 1 1 1 1 1 1 


1 1 1 


III 


ill 1 


1 1 1 


MSA.. ( . 




7?? 



Andrew Hewson 

I RETURN to the knotty problem 
of transferring data between 
programs but first I have some 
questions concerning peripherals. 
Peter Mann of Bedfordshire writes: 

I have been told that if I use my 
existing hi-fi cassette deck on the 
new Spectrum, the computer would 
blow up. Why should that be so? I 
would much rather use my 
expensive deck than have to try a 
'cheap* portable tape recorder. 

The Spectrum is a low-voltage 
device designed to detect and 
decode the kind of poorly- 
reproduced, low-voltage signal 
levels obtainable from the earpiece 
of a 'cheap' portable tape recorder. 
In contrast, a hi-fi system is 
designed to deliver an accurately- 
reproduced signal with sufficient 
power to fill a room with sound. 
Large voltage fluctuations are 
normal from a hi-fi system, even at 
low volume levels, and so 
connecting a Spectrum to a hi-fi 
system clearly risks over-loading 
the computer. 

To make the most of a Spectrum, 
you need it on a large table or desk, 
with TV, cassette player, books, 
magazines, pencil and paper to 
hand. 1 can understand that you do 
not wish to spend money necessarily 
on a portable cassette player but I 
am sure you would find it much more 
convenient to use. 

Recently I have bought a ZX-81 
For business use and am thinking of 
buying a ZX printer. Is the printer 
suitable for printing ready- gummed 
labels? asks John Modha, of 
Greenford, Midlesex, 

Unfortunately, the answer is no. 



56 




Peripheral 
difficulties 

Andrew Hewson answers more of your 
problems, including some worries about 
the Spectrum and possible add-ons 



Tha ZX printer is capable only of 
printing on the special aluminium- 
coated paper supplied with it, I 
suggest you look at advertisements, 
as one or two firms supply a printer 
interface which allows the ZX-fll to 
drive a conventional printer. 

Alan Pi tcher of Jersey s ays : I ha v e 
just ordered a Spectrum. Can you 
suggest a cassette unit to use with 
UT 

Sinclair has improved the 
cassette facilities markedly in the 
design of the Spectrum and so it is 
hoped that we will all find it much 
easier to use than the ZX-80 and 
ZX-81 in that respect. Instead of 
recommending a cassette player 
which might not bo available in your 



writes: I would like to replace the 
TV I use with my ZX-81 by a small 
monitor to obtain better video 
resolution. Can you advise me? 

I would not bother to use a video 
monitor. I have seen various TVs 
and monitors connected to ZX-flls 
and with some the picture is poor 
and with others very good. It does 
not seem to matter whether you use 
a video monitor or not. 

My preference is for one of the 
Ferguson range of small black-and 
white portables, which I find give a 
very clear picture and which cope 
well with the interruptions in the 
signal caused by the FAST 
command. 

I shall probably be besieged by 




area, I suggest that you choose a 
shop which sells a variety of players 
and take your computer, your TV 
and a typical cassette and make 
sure you can LOAD and SAVE 
before you buy. I have done that and 
found that shopkeepers are happy 
to help, provided you ask permission 
and explain the problem. 

My advice to Peter Stokes of 
Great Missenden is similar. He 



letters advocating another make or 
model and so I repeat the advice to 
'try before you buy'. 

Geoffrey Ottley is going to the 
States for three years and he asks: 
Will I be able to use my computer in 
the U.S. without further adaptation 
or will I need a new transformer? 

Electricity is supplied in the U.K. 
at 240V, 50 Cycles per second, 
whereas in the U.S. the supply is at 

SINCLAIR USER fulyim 



53* 



helplin 



120V, 60 cycles per second Hence a 
U.S. power supply will be needed 
with an output of 9V DC and rated at 
1.2 amps. It will also be necessary to 
use a TV made for the British market 
because U.K. TVs display 50 frames 
per second, whereas U.S. TVs 
display 60 frames per second. 

The U.S. version of the ZX-81 is 
also rather better screened than the 
U.K. version, so if your new 
neighbours complain of inter- 



being over-wrUien, copy the 
program area above RAMTOP; 
LOAD the data from tape in the 
usual way: create some space in the 
program area and copy the program 
from above RAMTOPinto the newly- 
created space in the program area. 
Obviously, to create some data to 
LOAD into a program we must RUN 
a previous program to read in or 
calculate the data to be SAVE, The 
earlier program could be deleted 



ference on their TV you will have to line by line but the process is rather 
put your computer in an earthed 
metal box. Perhaps it would be 
easier to buy a new ZX-81 on your 
arrival. 
Now I return to a topic which has 



laborious, so use this technique 
instead: 

First note the line number of the 
first line of the program. Suppose it 
is line number 10; then find the 



aroused a gooddeal of interest since effective length of the program by 



I mentioned it two months ago. 
Readers of the first issue of SincJair 
User will remember that I described 
two Basic routines for transferring 
data from a program, above 
RAMTOP, loading a second pro- 
gram from cassette and then 
transferring the data back to the 



entering PRINT PEEK 16396 + 256* 
PEEK 16397 — 16513. 

Suppose the result is 1859. Then 
enter POKE 16511, 1859 — 256* 
INT (1859/256); POKE 161512, INT 
[1959/256]: 10 or whatever was the 
first line number. 

Do not attempt to LIST the 



I 

k 

It. 



& 



UUHt 

R 5* 

PR1 

13* 

TO ST 
J.3* 



>&& 



pF^ 

i*o A e©Te %?&*& 




-A- 






%%£&** 






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variables area of the second 
program, thus enabling two 
programs to 'speak' to one another. 

Les Auckland writes; I would like 
to know how to SAVE and LOAD 
data only into a program held in 
core. Can you assist? 

There are two methods. The first 
is quick and elegant and consists 
essentially of writing new SAVE and 
LOAD routines in machine code. 
The second method is slow and 
clumsy but it is easy to understand 
and the necessary software is 
mostly in Basic, so I will explain it as 
the preferential method. The steps 
in outline are: 

SAVE the data of interest on tape; 
to prevent the program in the ZX-fll 



program between entering the 
instructions or you will have to pull 
out the plug and start again. You are 
making the ZX-81 think that the 
whole program is one monster Basic 
line and if it attempts to LIST it all. it 
becomes confused. Entering 10, or 
whatever, deletes the monster line 
in the usual way. 

The data can then be SAVEd, 
together with the display file and 
other odds and ends, on tape. 

The second step is to LOAD a new 
program and store it above 
RAMTOP, The technique is very 
similar to storing data above 
RAMTOP which I have explained 
previously. Be sure to move 
RAMTOP down as explained on 



page 168 of ZX-81 Basic Program- 
ming before LOADing the new 
program. The following routine 
copies a program above RAMTOP: 
10 LET J = PEEK 16396 + 256*PEEK 
16397 — 17509 
20 PRINT J 

30 LET K = PEEK 16388 + 256*PEEK 
16389 

40 FOR I = to J — 1 
50 POKE K +■ I. PEEK (16509 + I) 
60 NEXT I 

The routine PRINTs the length of 
the program. J, in bytes. You should 
make a note of it because it will be 
needed later. 

The data can then be LOADed 
from tape in the usual way. The 
current program will, of course, be 
over-written and so the final step is 
to copy it back from above 
RAMTOP. A machine code routine 
is needed for that step, because 
space must be created in the 
program area in which to store the 
program using a routine in ROM. 

The routine is 20 bytes long and 1 
suggest you store it at addresses 
32749 to 32767 by entering and 
RUNning the following routine: 
10 for I a 32748 to 32767 
20 INPUT M 
30 POKE I. M 
40 PRINT I, PEEK I 
50 NEXT I 

Enter the following numbers one 
by onefromthekeyboard:42. 12.64, 
229, 43. 1, 0,0, 197, 205, 158, 9 t 193, 
209, 42. 4. 64, 237, 176. 201. You 
might like to determine how the 
routine works by translating the 
decimal numbers into Z-80 
assembler using Appendix A of the 
ZX-81 Basic Programming manual, 

Before running the machine code 
routine, POKE the program length. J, 
into it by entering 
POKE 32754, J — 256*INT (1/256) 
POKE 32755, INT (J/256] 

Then delete the Basic routine, put 
the ZX-81 into FAST mode, and call 
the machine code routine by 
entering 
IF USE 32748 = THEN STOP. 

•i' Hewaon Consul tantb 19B2. 

• .Plnnse address problems und queries to 
Andrew Hewson, Helpline. Graham CJoss, 
Blewbtiry, Oxfordshire. 



SINCLAIR USER July 1962 



57 



PERSONAL SOFTWARE SERVICES 

MACHINE CODE GAMES 

THE MOST EXCITING INTERACTIVE M/C 
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16K 



£4.96 

DEFEND YOUR MGTHEft SHIP FROM THE ATTACKING FLEET OH TRY AND SAVE 
THE POPULATION OF A LONDON TOWER BLOCK FROM FALLING TO THEIR 
DEATHS. 



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AS HEAR GUNNER OF A SPACE CHUI$EH VOU HAVE THE HSSPOWSIBILITV FOR 
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Professional 40 key keyboard 

■ All legends and graphics in 2 colours 

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Kit £19.95 Built £24.95 Case £10.20 

Repeat key add on TBA. 

Range of in /out ports, music boards, motherboards, D to A 

converter boards write for catalogue. 

23 Way double sided, gold female edge connector, wire wrap 

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Male connector £1.25 
Ribbon cable £ 1 .40 per metre 
Mastering Machine code book £5.50 
Programming for real applications £6.50 
Tape for real applications £ 1 1 . 25 

HARRIS & LOCKYER ASSOCIATES 

(Sole distributors for Redditch Electronics) 
Dept SU Prices included VAT + p + p 

33 Pedmore Close Overseas add £ 1 SO postage 
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PURCHASE LEDGER. Keeps a complete record of ell your 

receipts under 11 sub headings. The program will calculate fr 

deduct VAT. 

SALES LEDGER. For all your invoices. The program will 

calculate VAT and list all outstanding invoices, 

All the programs will except entries up to £99999 99 & will enable 

you to produce your accounts at the touch of a button, Programs 

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16K programs accept up to 225 entries; £8.75 

32K programs accept up to 675 entries: £10-75 

Special Packs including all 3 programs; 16K £25. 32K £30, 

VAT & PROFIT CALCULATOR; £3.50 



Educational Software 16 k 



SPELLBOUND. Spellbound game for 1-4 players. Program will 
accept up to 600 words. Can also ha used to test spelling. tAJb. 
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41 Keats Ho., Potcbestet Meed, Beckenham, Kent, 

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ZX Software 



SCREEN KIT 1 more power to your screen 

in Basic programs 
BORDERS - any size - anywhere on scteen 
SCROLL in ALL FOUR directions 
FILL SCREEN any graphic or character 
CLEAR and REVERSE PARI OF SCREEN any parr 
FLASHING CURSOR - anywhere on screen - simulates INPUT 




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LOAD bKH irilo ANT orogrj m 
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•ttouh.le tn*Y commands tor Hex 

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REtlSTEBI DISPLAY 4 BHEAaPOWTS 

i SAVE, LOAD. VERIFY AT OOUBLE SPEED from any pari of RAM. 



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• IS owib* oammarKte UK HX prop immrni 
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Irom Basic area nf RAH 
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•ENTER, RIM. K-MJG miclwe code in Rim: REM linn 
•Operate hrirr above RAM TEN*. 
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58 



SINCLAIR USER Silly 1962 



Philip Joy considers a game of chess 
written for the IK ZX-81 and finds it is 
very restricted 

Simple chess 
limits moves 




TO DISPEL some confusion 
about Noughts and Crosses, I 
have received a letter 
indicating that 1 made two state- 
ments which contradict each other. 
"If you have ever played a 
computer version of the game, it 
tends to be very easy to beat", was 
the first comment. 

Thai statement refers to a version 
of the game which contains no skill 
at all — just the rules to play the 
game. As you would agree, an un- 
interesting game with little skill 
demanded. The second statement is: 
"Gives you a chance to win now 
and then, unlike many Noughts and 
Crosses which are which are un- 
beatable ..." 





That one refers to what happens 
if you insert a large amount of skill 
— it becomes unbeatable and 
boring. If, however, you have the 
computer learn by your mistakes, as 
the article was suggesting, it will 
become more difficult as you play. 
That will give players a chance to 
win, providing that Ihe player 
always plays to his normal 
standard* 

I was also sent a lK chess 
program in a neat package, with a 
cassette inlay created on the ZX-fll 
printer, with the instructions on it. 
The author is D Home, Cowbridge, 
East Sussex, I have asked for some 
comments from two other people on 
the game and I thank Ian Benyon 
and Leo Amatino for their help. 

There are some restrictions on 
what the game can do, because it 
had to be fitted into IK. Those 
restrictions are no castling, no en- 
passant, and no pawn promote. The 
comment on those restrictions was 
that it spoiled the game. I shall stick 
out my neck and say what I have 
always said — that the unexpanded 
ZX-81 cannot do anything construc- 
tive, except be used to control some- 
thing. 

I must also say that after I have 
seen the game, my mind is not 
changed. The game is satisfactory 
for IK but is nothing like what can 
be achieved on the ZX-81. 

Amatino says he thinks it plays 
the same game, and both he and 
Benyon say that it was a very short 
game. Home says it is the ultimate 
for the IK ZX-81; I suppose I hat is 
true. 




It is neatly packaged and costs £5, 
Amatino said that it was not worth 
the money. 1 would say that if you 
have a lK ZX-81, you could have 
some enjoyment from this inexpen- 
sive game. 

A Leicester reader sends details 
on the Artie Computing ZXchess II. 
He includes a game which I shall try 
to include in a future issue. His 
comments are rather interesting, as 
they support my point about the end 
game, He says; 

"The end game is less positive". 
He says of the save facility of the 
game: "The most significant 
advantage of this particular 
program is the save facility", 

A Cumbrian reader has sent a 
game played against Sargon 2.5 and 
ZXchess EL ZXchess won. He says 
that one bad move by Sargon 
clinched it. Thai is interesting, 
because I have a version of Sargon 
on my Video Genie computer and I 
have found it be be of reasonable 
standard. 

I shall include some of the many 
games which have been sent to me 
when I have played them and can 
comment on them. One reader has 
sent a letter saying that he did not 
know chess games were im- 
plemented on such small computers; 
he must be surprised. 

I hope you can send me details of 
anything to do with chess or mind 
games in general. Some comments 
on adventure games would be most 
helpful, as that is my interest, and I 
would like to know how oth«r people 
feel about them. 



SINCLAIR USER lulylBM 



5y 



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StNCLAIRUSER |uJy 39R2 



61 





IN THIS FINAL article we 
examine how our simple 
machine code routine scroll 
down can be used to good effect, to of the game plot. 



Playing games with 
machine code 

In the last of his three articles Mike 
Biddell looks at ways of using machine 
code in game simulation 



produce a game simulation. We will 
examine how a supporting program 
written in Basic can call the USR 
routine to maximum effect and how 
the whole program can be built and 
tested stage by stage. A logical 
procedure to adopt at this stage is: 

Decide the game appearance, 
strategy and rules. This must be 
considered in the context of scroll 
down, since we intend to use the 
routine we have developed. 

Produce a series of statements 
concerning the program flow and 



It is war-time and you are flying a 
transporter aircraft to land 
supplies behind enemy lines. As the 
runway approaches, you can see 
that it is mined but it is too late at 
that stage to pull up, since your 
airspeed is too low. You have, 
therefore, to land and taxi around 
the mines to take off again and see 
the runway recede. 

If you hit a mine or go off the side 
of the runway, the aircraft crashes. 
It sounds exciting, so let us proceed 
to the statement portion of our 



operation. For a program as small development plan and produce a 

as this, a full-blown boxed chart is series of statements about how the 

considered unnecessary by the program might flow and operate, 
author. Main program loop, using PRINT 

Using the statements, build-up the AT function to produce the runway 

program piece by piece, testing as element. Call USR to scroll that 



you proceed for the desired effect. 
Soak test the entire program for 
several hours, by letting your 
friends, acquaintances and 
children loose on it. If there are any 
undiscovered bugs they will find 
them- 



element downwards. Put the USR 
call in a loop and that should 
produce a moving runway effect. 

Add the aircraft path by adding a 
POKE statement into the loop. Allow 
the aircraft to be steered left and 
right by using inkey $ to modify the 



Figure 1; MAIN PROGRAM LOOP 

% PPM 5iRME» ? m i FS5T i*57 * CLE" 
RR FRST SGN LPRIKT : t<S** PRINT 
TRN MMMMHMMMMMHMMHHMMHHMMHMMMMMM 
MMHMHMMHMMMMMMMMMMHHMMHMMMHHHrlHH 

MM 

3 LET T»165it 

7 print at se f 9;"HanB#r 
IB PRINT RT 1 ,!©;"•* 
£0 LET A=USR T 
50 GOTO J.0 



I have always had in the back of 
my mind the thought that scroll 
down would produce an excellent 
moving roadway or airfield effect, 
so we will build the game around 



POKE address. Scroll down should 
create a plot of the previous 
positions of the aircraft. 

Within the loop. POKE the mines 
on to the runway, in varying 



that idea. If you have other ideas for positions. Add the logic for a mine or 
a pp lie ati ons of the routine . fee t free verge collis ion, That should send the 
to pursue them. Here is my concept program pointer outside the loopfnr 



a comment and game re-start. 

Add program to advance the 
taxing speed of the aircraft as it 
proceeds. Finally, incorporate 
program lines to signify a win; 
create a receding runway and a 



FiRur* 2: VDU PICTURE CREATED BY 
MAIN PROGRAM LOOP 



*-*■ 



jump outside this loop to comment on 
the win and allow game re-start. 

Now let us make a start with the 
main program loop. Delete lines 10, 
20, 30 and 40 of the scroll down test 
program and add lines 7. 10, 20 and 
50 as shown in figure one. Line 7 
prints the game tide on line 20 of the 
screen; that is not scrolled, since 
our routine scrolls only 19 lines. 
Lines 10, 20 and 50 produce the 
approaching runway effect — study 
this three-line loop carefully. 

Then run the program and you 
should see, if all is well, the runway 
approach. Press BREAK before the 
runway reaches the bottom of the 
screen and you will have a VDU 
picture similar to that shown in 
figure two. Our main program loop 
incorporating the machine code 
works. 

Now add the aircraft path and 
some means of steering it, I have 



62 



SINCLAIR USER My 1982 





machim 

cod' 



y> / 






yf, * ■% y. -)C 



i V^ 



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V7 4 V 



chosen an asterisk (*CHRS(23)] to 
represent the position of the craft at 
any time. Since we will be POKEing 
the asterisk into the display file we 
will have to locate it, a a described 
previously, by PEEKing system 
variables 16396 and 16397 and 
using those to define a variable YY\ 
Then add the following lines to the 
developing program: 
4LETV = 411 

5 LET W = PEEK 16396 + 256* PEEK 
16397 

30 LET V = V + (1NKEY $ = "&*)— 
(INKEY S = " 5") 
40 POKE W + V, 23 



Variable W in line 5 defines the 
start address of the display file and 
variable V in line 4 is the dis- 
placement to be added, to position 
the asterisk in the correct place on 
the screen, 

The POKE statement in 40 places 
the asterisk on the screen, directly 
below the runway. The value of V 
was determined by trial and error. 

The steering logic is in line 30. It 
uses inkey $ to decode keys 5 and 8 
on the keyhoard — the keys with the 
left and right arrows. That works on 
the basis thet if inkey $ = "8", then 
the whole expression inkey $ = "6" 



is given the value 1 (true). That 
applies to inkey $ = "5" in the same 
way. Thus, if inkey $ = "8", that 
adds 1 to variable V and moves the 
screen POKE one position to the 
right; if inkey $ = "5" it is moved to 
the left. 

Then run the program with these 
additions and you can steer the 
aircraft from left to right. With its 
controlling logic, you can steer it 
anywhere you like, including off the 
runway. 

We have covered items one and 
two of the main program speci- 
fy ca ti on a nd I have been doing a 1 1 the 
work, It would be excellent practice 
for you to add your own program 
lines and complete the program; test 
them carefully as you proceed. 

For those who feel less inclined to 
tackle the task, a completed pro- 
gram — it is only one solution — is 
presented in figure three. Compare 
the additional lines to the rough 
program specification and you will 
begin to understand how it 
operates. To be frank, I have not yet 
managed to get the aircraft back off 
the runway. Is it possible? Perhaps 
with more practice I might make a 
better pilot. 

In conclusion, if you have 
followed the articles, you have a 
mini-machine code loader and an 
understanding of how to write 
simple machine code and in- 
corporate them in a Basic program. 
It is not too soon to be thinking about 
your next machine code challenge. 



Figure 3: "HUNWAY" — COMPLETE PROGRAM LISTING 
(Basic end Machine Code) 

OB FfiST 4n LPBINT : <^5* + PRINT 

^R^MflMMMMMIlMHMMMIlMhMMMMMHMHttMM 

MM 

2 LET S=0 

3 LET T=135l4. 

5 LET W=PEEK 1&39&+2S6*PEEK 1 
6397 

7 PRINT RT £0,9) r **laHH^il**' - 
10 PRINT AT i,^;"* ■ ™ 

20 LETT ft=USR T 

21 LET R=INT (5/10) 

22 IF S-Rtll?^ OR 5-R*10=t= OR 
5-R*10=4 THEN POKE U+U-33*INT (U 

^P*l!t S 5 = U + CINKEY* = "6"> -(INKEY 

35 IF PEEK (U+U) =3 OR PEEK tU+ 
U> =52 THEN GOTO 100 

4.0 POKE U+U,23 

4.1 IF S = 1O0 THEN LET U=U-6S 
4.3 IF S-150 THEN LET L'=U-33 



4-3 
4.4. 
45 
50 
100 
110 



120 
130 
14-0 

?5P 

* = '*5 
270 

£9fl 
30O 
310 
320 
4-00 

PLRy 

4-10 
4-20 
4-30 



IP S=200 THEN LET U=U-9=l 
IP 5=250 THEN GOTO 250 
LET 3^5 + 1 

eoTO 10 

POKE W+U,61 
PRINT ftT 21,0; "I 
M REPLAY V/N? 
INPUT Y* 

XF V*=-V" THEN RUN 
GOTO 120 
PRINT RT 1, 10; " 



LET U=U+ (INKEV|="8") - f INKEY 

IF PEEK fU+Ul =3 OR PEEK (W+ 

TYi^H GOTO 100 
POKE U+U,23 
LET 3=S + I 

IF 3=270 THEN GOTO 4.0B 
LET fl^USR fT) 

GOTO 250 _=.^-™=™=«— = ne 

PRINT RT 21 ,»; "■t-W^I^MH RE 
Y/-N?-' 

INPUT XS Mn 

IF X*="Y'* THEN RUN 
GOTO 410 



SINCLAIR USER July 1982 



63 



competition 




Win a 

printer and 

a Memopak 64K 

We thank readers for all the entries to our previous competitions. 

No matter what the subject, it seems that readers of Sinclair User 

have little difficulty in meeting the requirements. Many of the 

tie-break lines are most ingenious. 

For our fourth competition we again offer a printer but this time 

couple it with a 64K Memopak from Memotech of Oxford. 

In line with our policy of fitting the competition to the prize, we would 

like you to write a program for 48K RAM. All entries must be on 

cassette and accompanied by a typed or beautifully-handwritten 

listing. 

Your entry must reach us by July 12. 

As a tie-break, should one be necessary, we want you to write a 

slogan begmrung with the words; "I bought my ZX-81 because " 

The usual rules about the editor's decision being final, and employees 
of ECC Publications being ineligible, apply. 



\ 
I 
\ 
\ 



, ♦„ rite slogan, w" 
a3Hll because. ■■ ■• ; •■■ 

Name 

Address •• •*' ^\s\*&°« 

^rtianl^V l2> 



Green 



\ vrCPubncaU° n 



I 

v 

\ 

■ •••" 1 
London \ 



64 



SINCLAIR USER fitly 19B3 



ZX81 SOFTWARE 



ALTS HMATIVE PROGRAMS (I-IGK) 
FOH THE MORt DISCERNING ENTHUSIAST 1 
CASSETTE 1 

UATHSatlt |t«KI 

4TT t*i 1 lOI* AH PAHENTS^ PraimsKl B» pn«ncl» in *r«c1ic*l Ci»i*"iiH9 Uan * ' I Dm 
itaiw maim Kfliwirii. *• Seciifml H urixiuci ■ progrnr" i"r"i *W*1 fli« *ni" i 1 "*! 

nuHttm ihr in 'J'«Uy nn'»vip.i*in*rDm3 inf«o««i v MATH&ONE wi||>.i> - 

:Md Hinii hi in* lomil wbw ■)"<* 4*r.uJ*t Hto» ■"■•<* ht.'Hir hM g0"< 

„,„, w,,r. rri* -*hol« wni it IKIflMA W "I* hihh|uw «■ lha rlw*! miulfl rt» W«t*1 p«l 

IMTH*IUTilTt«] 

Wr *nasfl mllir«hji*r c*n *ieBch ih* cwmi 1ii ir r*i: 1hB njm* tiw^mi mwe intf n^D»ff 

cfctficiHI' __„ 

MmlttOMi » MjtlH**r» Ea*S 

CASSETTES 

LANGUAGE THAWS LAIOI4 

Hiring rut-rnHy wiin Inrnigp mr' T>«l m~rtr.li* program lor>«u' r air*oid Irji wo"J 
Mansions" 'mm »U0 uwxds inwimii Worrhcnn nnnl* ** LiMlKIKl *"« 5AYE0 i»ri 
mp* Pi«ittfcLBEfl inguiuwi:hn«« 

IMORD T 1ST 

Far iha *cv i^n^ir ™*rrvty»n <* irw l a mih*.wrJHt> TEST wm »■>■ < Inidmn rwtlttty 

compirtnd wrjidi Second lrya »rt n llu*tfd ml in* v:er* M OH tin Wllh CWHTI 

aFTfiwcrinrt^iii"-' 

Laficfij*acT^«Ti*ljirtr h *wrj 'rtf l T -I- 



CAS5ETU 1 

BAK« ACCOUNT HEKl 

WNl <*»'' tor J Ji*i*menl w*e*i vuu r.*n niiii yo.ua siwi iwiiMQnal ti*n* flg ■ 

■ ■ . -.ran W19 orflfln >*i rtw ,|iuil *iy onrl will ■** y^" nfi™ voii* n»l* n £* '■ ■l"'"'*' 
iiif b«« b**ir»j imii men KHi HIt tfi*igc ym H<?r '■' J"« I'k* rn* rj«n» ' Siihi»mmi n*n 
i» cockdiiBd HnrJ ud la ISO trwiiirJicra tin h* H 

HOME. BILLS HEAO* HtCKONFB 

*V iM la buijm (Ttaur HBcrrtihY/tBlMinon*;'™! put mn corr*n J 

fian* Ai:coiinr + F#anh'flac'tar»pr f3 9& 

PI EASE NOTE Our»Hmii« n or IhK uzr, >ii|jtinn isu*H> ind atir»d»lwe"*'i|i*'**nri 

inu »•<¥ bnt Mn ita Sincloir irtfUe «r«l »w*n ,» *« u« Mt ou»i»1vm ticnih (h>! 

Ilwulmil 

r+oNpaw>ef>fiii«'cflnnpijii^;! MjdJfirJnm' 

VOUB OHCtfl IS RECEIVEU AT H.jD Ar*D IS DE-SPATCHtt!) IV 1 2 JO THE SAME 
D*v 1* UAf MONEV BALK tHj»»ANTEf IF «*' fiAnSFlEU * B MONTH 

il£V£rv T C-k.iAP.ft'iTlrt 



***** crwqutM, /» A prcpa^aftfe in 

FUTURESOFT 

38 PENSHUR5T ESTATE. PRINCE OF WALES ROAD, 
LONDON, NW 6, 







/ \ m 

tHSKU 

turn t.i-Wt 



♦ M^MHMflj W 




i/ # ■/ Jf J/A /MOW * 

* H 1. 1 I. EA Gt / J A BL fi S • 

* /\J( //// s * 

irJLE iNsoi n |) * 

* vi w <. iw-* i< it try* 

^= * u i \ !(,/«/ 1/ RUfMj* 

* /'/<A IfJffr ff.-l.-Vf /-T JJ? fi ■!<:// M/i rt'/f » f. i- r ir * 



Ml 



lltio h \< H' d nii-ri- iintuljli>in. I Im t% an I'SidinL!. jml diyhlt .■ n 1 1 ► \ jIiU 
tJPHi' in »lm;li urn |i tu-* i In |url n|' a l-oitthdll Mjiuiir toping »ifh Ihr 
tirnrhliitu diul ili'i cmkc initphrd in runninn iimr rlub. Iherr aft Ml mm) 
I'ritlHIVx ir h imLHi-Mhli- lu li>l llicrn hrre bul imlmlvd *tv lorm 4 1 up 
[I'jms MlK VI M IV nin}„ ^iiin I -killings, »a|{r hills Hi pa>, antd » »u van 
*-n-n Ek- sjiki-il! It is * (iiinii' r^utrin^ u ^rt'al dtiil of ^kill. anil ptupk 
plit> LI fur IHitjIK huur> urt rnd (»r havr prm>f!9- 

U I i .1 VK \\ I t > Ilui Itait. \\ one ill (hi- ljf.1 ciiMlpHtlrr KMmt> )<m'** 
i'nr pljit'd! 

HI I Hil-W AHI.. Iln> KJrnr ii r\lrtm»h idiiiiliM' 

I II miuii 1 1 LIEU II I li Eiiii.T.ilEr.lUttW.UmLUHI." Til J I .hi. I J I J i.t.i r r 1 1 r 



l-'OOTBALL MANA(.KK 



tin ii mi f\sikvcri(i-*\ 

■> tlil t \llkl /*A rV IW 



HAKI1WAKK RKOriKI Ir 






Hh ROM 

It,K H I tJ 



TRUU}> 
I itfett liemt 



tt.lt Ul 
/ftfi ft I \f 



lit 1,'nU'r ■•rt/i t %tq¥*/f*.Q. E7iffi 
nJi«fr/wjw/i/f «.' 4WJKT/I / f, 4 VI. 1 ^ 
j; />r P r V.(. f'.fl, W*AM?I 
( (twim umin 

Mil HH, KEYNES MKI4 W« 




TRADER 



It is hard enough to look at an amorphous 
hydrosilicon blob from Psi, never mind swing a deal 
with one. But whan they ask to pick your brains, do 
you really know what they have in mind , , . 7 

Trader' is B new concept in ZX&1 games. It is a graphic 
adventure so big that it fills your 16K Ram three times. 
You are an intergalactic trader and the life is tough, the 
bargaining hard. You can make a fortune or end up spaced 
out in a Delta n hellhole, 

"Trader'. 48K of adventure that wili run in your 16K Ram. 
It costs £10.50 inclusive. Send SAE for more details of 
Pixel games. 

PIXEL 

Pixel Productions 39 Ripley Gdns. London SW14 8HF 



Professional Grade Keyboard 
and Case at Unbeatable prices 

#Our case takes the ZX-81 printed board 
♦Keyboard supplied fitted, to case 

* Your Rani Pack plugs into rear of case 

# Assembled Keyboard and case price £3*i-00 
*Kejrboajnd complete with ribbon cable & connectors 
*N<j soldering required 

*Large kevs are used with changeable keynwktns 
♦Keyboard ready assembled price £24 .00 

* Sinclair makes the best home compute™ 

and we make the best keyboard** 

*i-'ull momy Iwck guaranty if you an- miStstlly sahsftt'd 

'I'nces indutif VA T* 

♦ lfiK Ram Pack — fullv bested, ready built And in a cast 

Uses existing power supply. *S'J"AR BUY - £28.00 * 

Ma H Order Address ; Fkzwwldl ISO K\J ' 

<;< > K I H »N EL EC TR< » N ItS JMafcrcfc^m A™*4 to 

7(> Momitbaltcn H«ad, GQBiXWEm 7WCWK5 

Uraiiitret\ Essex LM7 GTW Tek-phont: IQ376) 26048, 



S INCL AIR USER July 1 952 



65 




7X81 DATABANK 1CK 

Serious- Programs Irum 

SANDERSON SOFTWARE 

1 3 programs on one Tape 

1 Creale your own Lnyoi.i1 

* Vocabulary Keyword texture 

* Add, Son, Search, Oeleie 

yn-ur nwn Databani: 

* Change Data (r, Curat" Select 

Many Ssrpu* Ui«*; Job." Work 
Programming Multiple Indexing 

Disca . M us it Library, ajtc, 

FSrncI p&p and documentalinn 

P.O. o< Cheques la: 

P Sandersjon. 1 Manor Court. 

Braasinn, UEHHY DE7 JAW 



1X80 ZXB1 

SOFTWAflF 

ZXAduanturtTap- I fS.QO 

Greedv Gulch, Pharaohs Tomb. Mann: 
Mouniam - 16k RAM required 

Th* rtlowoimk Punle h I 5 00 

Olher DivErsmns 

Three anginal programs to puule arm 
mturi4(o f Includes a fasi mtwtttbH 
rii»mrjli(.(in game lSKfiAM 

ZX81 Pocket 8ook £5 95 

1 3Spp ol programs, articles. <jsefui 
Srjbmulinft. plus treats your DwD 
Advenlures.1 

AigmBunrHH C6 95 

Twelve programs for in* espanded 
Acorn Alum • sales graph, nominal 
ledger plus much more 

ZXH1 Fwrkflt Book Ciffitnt fSOO 

Alpm Business CaasaTt* tS 62 

Mailorder Phipp* Auoc letea 
Mail Order Pep! F 
99 Easr.Sr.reer. 
Epsom Surray K'T"I T 1 £A 

Phone Access/'Bardaycard orders 
Ee*om<Q3727>2S21S 



MANSFIELD COMPUTERS & 
ELECTRONICS 
^ PajftcMfe Care 

Mans1<e4d 

Notts NG IS 2-Jfl 

Phone 10623! 3! MB. 

Srrn;kisi3or GENIE, ATOM, VIC 20, 

ZX8T, PKis kar-os range nl software. 

Ktestn¥4es & honks 

SPECIAL OFFER 
2X81 PRINTER PAPER. 

TOP DUAL ITT 

€ rolls. Iftr only E 10 $5 lot . 

VAT. pEtc 



"EEBEE" 

"*AT LAST", a serious 

money making program 

with setf check ami file 
storage 4K. P3.96. 

"SAILING", fight winds, 
currents, hazards, adpusi 
sails and rudder to reach 
harbour before storm 
breaks. SK C3.86. 

For JtX$1 /Spectrum. 

Quality [apes, error Nee. 

Cfiecue, P.O. io "EEBEE" 
"EEBEE" Computer Wares,, 
20 W«nstree Basildon 
Esse*S513 1PG 



ft> UCA TiOHA L SQftWA WE ZXB 1 1 ISKi 

act. "0 1 Level french 3 h«kj 

programs Grammar plus 3 llulti pjrrrgrams 

Vocabulary 

G C E. "O"" LEVEL MATHS: 1 41610 laaeh 

and lest program pJus 2 I IGKi programs ol 

generated ciunsiiiins Irnm "0" LevBlsyllabua 

iwirh eipla»iS[i'.;nb,l 

EDUCATIONAL OUIZ: * n&KI prngrAms 

on kenaral Knowledge, fi Basoning. English 

0'iiJ MdlhK. All qinCTlrnns use H NO func tHWi 

JUNIOR ENGLISH 1 IB 13 year*! Msan- 

mgs 1 . MeanmyS 2 [harder I . Porta oF Speech , 

Proverbs, Similes. Anagrams. 

JUNIOR ENGLISH 2: Idioms, Oppasnas 7. 

Opnnsites 3 Iharder!.. Group Terms, Odd 

WurdOul. Spellings 

F4 50 per casseTte or send sue fox csialrxjini 
tr:: ROSE CASSETTES, MSWidnty Lane, 
Sc4ihull Wr>s1 Min^inrls B91 31 H 



ASTRO-INVADERS 
(16KJ 

Superior machine code program minsj. 
f»sl action space graphics, a new 
di mansion irv ZX -8 1 vbIue 
1 explosive on -scrn*n kill ntfrjet 

* hifjh-lCQnrigSAuCGrs 
■ &i*UJtckir>gal>Bns 

" tccnlarathno attack rata 

* tJestructable delencE shields 

* contin uous storft dhi! high ■ score 

On cataetta with four BONUS 
flam-as: ARCADE GRAND PRIX 
(machine code akrll, 4 levelij 
PENALTY | gel ready for Spain 82 1, 
GOLF 4 judge shot stength. angles. 
bunker* and maybe hole in onell, 
pi us fun SWAT 

S games oil *re t»**etl*) Tor only £3,85 
tpoar tr^iifl fjrdar now Irom John 
Prince-. 29 Brook Avenue, 
Lauanshulme. Manchester. M.I 9. 



ZXS1 SOFTWARE 

Database 

Am*/.ngiy vE'isfiir program jrilQrtnivg iha ^raiiiQA 

Qrf npHj fll EEy Map iP^h>i *nv (l-.ing I rpn il?ch ■ 

GOAtrvi ttr«rn(?lrjy» drcDrrli, ami mnra tenures 
■nciude jdd, dtlETi-, updan. piifl I. turn. cEMfftj 
au« aar and * ai n>- l«ck. Suppl wd Hilh da iaUrd 
rtOfiprfiawlllHiE'l inrJ I«k LD"iai"fiir*fl nw iamcMat 
tiin. EiEr'^frr va ; u* ji dhIy TID 

BUDCf T/ADOfl ESS-BOOK 

6U0<jET null record all pour rticoffirt*i|M-h<ji,r,iir* 
Iw iwrrt or tMhr:i budoa-rring 
ADnnESS-BDCIK m B in1»u>i a i>n a* rani. 
adrtipryrr jnd le+oriirjflf ri-umbari Uan rmac^irw 
CDdf lar Fair aLgan Baih flroqr#mi TrK ?niy £4 

EducaliDnai prG^ami aviilalMa iA£ludiha 
«QflDETQFlF.C|yi?PACK, F UUCT ION PLOT, 
STATISTICS. 

Said SAt for lull dariili u ( irnr w mrj oihar 
tHqa/arrn 19 

JPURVES 
I 7 Slonn.il Road. Go,.i„ nag,, VKr>Dll>ian 
EHJJ<FL 



ZX31 COMPUTER + r6K:RAMin 
superb condition, all yours for only 
£100 o-n.o. Phone 01-462 T614 
after 5pm. 

ZXB1 16K "RENUMBER" Hn 
number your program lines, in* 
duding GOTO's and GOSUBs, us- 
ing this general purpose utility 
routine. Recorded twice on high 
quality TDK AD-C46 cassette. 
E3,S0all inclusive. M,R. Irving, 22 
Wheatley Way, Chalfont St Pat«r, 
Bucks SL90JE. 



SPECTRUM - ZX81 

BUSINESS 
GAMES 

AUTOCMEF As MD you musi neg^Hale 
lor lEAfans. ojacida on menu prices, level oi 
wages, advertising and dividends and 
(rirecasi lavels til inflation. It you are rwi 
au<:(Eislul ynu wall be nxnde to resign! 
AIRLINE Yon must decide on number «l 
autrah in ii5Mrf»tr. loan and luelcorilracts, 
wrhether to buy ot charier, and levels ol 

:, billing and maintenance 

rtfluxv specify nftrnput&r w/ion Qtdanng. 

Each program makes us* of 
HISTOGRAMS and BAR CHARTS and 

uses 15K. £4.'rTa each at ('BOO In* nrvo. 

Crt ^y 14 Langlon vVav, 
%^T . O a Inndnn SE3 7TU. 
^~ " *■" * Tel. &1-8Sfl 0763 



ZUCKMAIM 

I16K) 

The first ZXB1 version 
of Packman 

# Aff Machine — cede 

# Trail, Ensrgy Posts t*tc: 

* On-scraan scorm, high score 

* Authentic action 

only £5,95 inc. P6P 
Sand cheque or P.O. to: 

D. Looker , DJL Software, 
9 Tweed Close, Swindon. Wills. 



ZX81 IK Sinclair built with large 

keyboard in case plus I/O port and 
various programs. £30. Bob 
Wiicock, 41 Berwick Road, Wood 
Green, London N22 101 , 889 3571 . 

QUALITY IXB1 SOFTWARE. 20 
Superb IK Games (Inc. Machine 
Code), E2.75, 16K Utilities in 
Machine Code, £3.25, IK Utilities, 
£2.25. 16K Machine Code Editor for 
the Serious M.C. user, £3.50. 
B.ftAO, 13 Parkstone Close, 
Bedford, Beds, Tel: 1 0234 j 48243, 

ZXB1 COMPUTER, 16K RAM 
+ QS prog,, Graphic Generator 
and mother Board + £50 worth of 
software, inc. m/c invaders. 
Worth over £220. win sell for 
£160, Contact Banbury FJ4BS6 
(After 5pmi, 

ZXS1 16K almost new, DK 572 Pro- 
grammed graphics + 512 user 

definable, Kay DE keyboard. Books. 
basic + machine code. Tapes 
Games - Invaders ■ Chess etc, 
Machine code Assembler/ Dig' 
emblers. Total value £250 + selling 
£170 Dave Noonan 01-272 5674. 

At last ZXB1 PHEONIX In 16K. 
Expertly programmed and recor- 
ded. Only £3.00. cheques/ FO 
payable to A.R. Hill, 29 Trimdon 
A ve , , A c k lam , M iddles b ro ugh , 
Cleveland, TSS 8LU, 

ZX81 TGK ARCADE GAMES. 

M/C Missile Command and 
Galaxians £4.96. M/C Asteroids + 
Invaders £4.95. M/C Falklands 
Islands, action packed adventure al 
£4.96, all on cassette. Magnum 
computing, 3 Wen sky Close, 
Harpenden, Harts. 



WANTED. ZXB0/B1, Vic and 
Atom books. Half price for good 
condition. S.a.e. for buying/' sailing 
lists, or books direct 10: Allan Guy, 
24 Woodside Drive, Cottrngley, 
Bingley BD16 1HF 



ZX81 +16K RAM Sine. Built 
Adaptor, Manual, DK4K ROM 
+ literature. Software including 
Chess, Startrak and many more. 
+ Prog. Book. £T20o.n.o. the lot. 
v.g.c. Tel: Wokingham 782947 
after 6pm 

ZX6T MEMOTECH 49K Module 
c/w PSU, Cost f 140 used once 
only. Will accept £90 o.n.o. Phone 
Newdigaie STD (030 677 i 274 after 

6pm. 

ZX81 MICRO-COMPUTER with 

16K RAM and £20 worth nf soft- 
ware on magnetic tape with manual 
very good condition, hardly used. 
CBS o.n.o. Tel; Barnsley 102261 
42143 between 2. 30pm to 8pm for 
further information. 

FOR SALE - ZX80 BK HOM 16K 
RAM manuals. Many pre-recorded 
programs inc. Sinclair business/ 
household. Chess, Labyrinth . . , all 
perfect working order. Accept £120 
on o, Tet; Northampton (0604) 
831078 

ZX81 KITS Cure Top Line S&anl 
and Ram Pack Wobble £2,95, 
Inverse Video Module £2.95. Built 
£3,55, Repeat Key £3,75- Built 
£4,96, All Kits ex -slock. Please add 
40pP/P, 

ZX81 with TBK RAM, Also many 
programs £S&, ZX80/81 40-key 
Keyboard £15 Both items in good 
order. Phone Atherton 87941 3 after 

5pm. 

FIVE ZX-8t graphics games — 
VAHTZEE, PONTOON, 

MOONLANDER, NINETYNINE, 
BLA STOUT Tape £4 00, Listings 
£1.00 each. Many others available 
including SOCCEPFILE, see- 
details Adrian Boone, 1 Church 
View, Tobermore, Magherafelt, 
Co. Oerry. 

"ZX81 MK USEABLE RAM, PI A, 
EPROM. professional keyboard 
and case jincl 6 spare keys and 
space beri. Programs + Books 
value £30+ , Cost over £260, Sell 
for £200 o.no, Tet: (0642) 782719" 

SINCLAIR ZX81 with Keyboard 
Sleeper. Sinclair 16K RAM pack 
manual and two books, and 
assorted micro computing 
magazines £100 0,n.o. Ring 
Stevenage 721659. (Herts! 

ZXB1 STORE/SORT PRO 
GRAMME I16KI, Store, sort and 
order 100's of items of information 
and emend as required. Tape and 
instructions £4.95. J. Blackford, 63 
Eltisley Avenue, Cambridge 3. 



66 



SINCLAIR USER fuly 1982 




16K PACK 123 



Pack 1 i fcr 3 include alt of: 

AIR TRAFFIC CONTROL.- Animated radar screen at tn»v *irn*iri shown You 
must bring planes fato bind: IHVADSRS SELFPLAY; PHONEBOOK -- keep 
Iticrnh' emj relaiives nombflrs nn carjmttr- COMF'L'l E<i DATtNG. who W* il 
pick tot vou find those around you 'o* * levDjh ADVEW T UR E AT LANT IC' you 
may become wary rich of marooned forever, BREAKOUT. SQUASH: 
LANGUAGE TRANSLATOR: rtanadatae any European lenrjiiag* lusny other. 
COMPUTAPUNT predct hot™ i«cn and football pools win you /X 
iNDISCO. video roadraeer. DRAUGHTS computet chequers. *Kh kings 
BATTLESHIPS, nauttiaJ naval banle at noma MASTERMIND: brain leaser, 
sea if you can beat * micrnriiMirrrHt mind 
THIS MASSIVE PACK OF SOFTWARE IS ONLY tfi-WJ 



tifc^ ZX ADVENTURE 

A brand new release, this, package of adventures written «i Basic arid Machine 
Code aw the best value and quafaty «v<<atile. Just compare them with othetll 

1 . GOLF : on* or two players have a matchpiBy off with handicaps and progress 
around an IB hole coune wFadh is superbly detailed with bunker*, lakes, trees, 
busties. and greens. We Iran* ynu will agiae this game Has (he best gr aphic* 
aviillitala tor [he ZXS1 

2. DAMSEL IN DISTRESS: you a*e Hie anight in shining, armour, your cjuest is 
to nde tin a vast castle and nn* your princess and) rnkHs* her hum the 
dutch** o! an evil witch. You must r|njam up a spell to destroy the old witch 
and colarci enough gold tc bribe the awards A v**y BBwiicrwng Adventure 
p/OQ/am 

3. STOflM THE TCrWER: as the General of s medieval army you must deploy 
your irim end men so vou can attack an emjimaui castle with a huge lower. 
You muEl build timamant* (rid prepare lor the correct hour to aruck but 

beware of rearguard action and cunaidar "nteidgance reports with carol 

ADVENTURES £8.00 



ZX BUSINESS SYSTEM 

MGrt :nirj!letl n many busineaie*. come* *-. Ili PURGHASt . :iA.l I S I L CM ,L R 
tur 100 * entries par week, does daybook analysis, VAT mcl and fMl torab, 
pa**wurd proKKoon plus many more BkceHem features. You <^og*i9 STOCK 
CONTROL. MAIL LrST and PHONEBOOK. Easy m use. designed lor everyday 
small businesses Includes instruction iirKik and 1ii[5e f17.DG ind VAT. 
And don the job ol systems costing hundred* of pound*. 



ZX AUTOCODER 



Writing machine code? 

Soma Tows k, some hate it but AUTDCODFR luatgeti on with il. Helping you 
produce nuelww cods- proarams from BASIC Easy to us* and var> helpful. 
Convert* PRINT, PHINTAT IF THEN, GOTO, GDSUB. LET INKEV*. POKt. 
PEEK, CLS. etc. 

ALL£B.0ulncl 



ZX ARCADE PACK 



Machine Coda Arcade Games 1or »6K RAM 2XR1 

These Classic f Aftchme Code games come together f or £5 00 on one tape ■ 
We guarantee these are the Best Value & Best Quality you can u*i, 

INCLUDES 

MfQ BOMBER., bombs, mwsikM. (hrvst up down two types at ALIEN. 

GALAJtIANS, mcteaiLle swooping and bombing enemy lighter 

SPACE INVADERS No ooubl the bnl version avaia&ka, several Al*ns, 

numulmg defences, wave after wave el ekcrtemenl. 

PLUS MANY MOflE ALL ON ONE TAPE FOR C5 00 

' H ihis pee* is not 1he best you've ever had we will relund your J'EvQO 
• also AT GOOtJ Computer ShOI»S!i 



AM prices incl. VATR and pftp P Iodic aend 10 

CONTROL TECHNOLOGY 39 Glouceater Hoad. Gee Crow. 

Hydo, Chaabrra SKI* 5JG I Hi 368 re6fl) 



SUPER SOFTWARE 

AVAILABLE FROM 

CONTROL TECHNOLOGY 

NEW RELEASE 
Trident (Acorn Atom) Death Race 2000 (VfC 201 





Air Traffic Control (ZX81) 



Warlords (Vic 20) 




Moroids (Vic) 



Astro Battle Zone 
(Acorn Atom) 




Breakout (Vic 20) 




Draughts (ZX81) 




Maze of Death {ZX81! 



qjh irst nrjr.'t t-'*i c to e 

HIS HfJUE FRPM 



Breakout (ZX8H 



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Please send me as soon as possible the following: 

n c 

□ ^ . £_ 

I enclose a Cheque/PO- for the total i 
NAME 



ADDRESS 



POSTCODE 




I 




KA YDE Electronic Systems 

ZX80/1 

ZX KEYBOARD WITH 

REPEAT KEY 




Fully cased keyboard ........ £37.95 

Uncased keyboard :.. £27.95 

Keyboard Case. £10.95 



This is a highly professional keyboard using executive buttons as found on lop quality 
computers. It has a repeat key and comes complete in its own luxury case, This is a genuine 
professional keyboard and should not be ganf used with toy keyboards currently available on 

KAYDE 16K RAM PACKS 

The 16K RAMPACK simply plugs straight into the user port at the rear of your computer, ft is fully com- 
patible with all accessories and needs no extra power and therefore it will run quite happily on your Sinclair 
power su ppiy . 1 1 d oes not over- heat and will not lose memory at all , As you may k now so me makes go daw n 
to UK after being on for a while, 

This 1SK RAMPACK is very stabtaand will not wobble or cause vnu to lose your programme. It comes fully 
built and tested with a complete money back Guarantee. 

KAYDE FLEXIBLE RIBBON CONNECTOR 

Stops movement of RAM PACK and other accessories 
(Not needed with a KAYDE RAMPACK) 

KAYDE AK GRAPHICS BOARD 

The KAYDE Graphics Board is probably our best accessory yet. It tils nearly inside your ZX81 , It comes 
complete with a pre-programmed 2K Graphics ROM. This will give nearly 450 extra graphics and with there 
inverse makes a total of over nine hundred. 

The KAYDE Graphics Board has facilities for either ZK or RAM (for user definable graphicsl 4K of ROM or 
our 4K Tool Kit Chips that will be available shortly, All the graphics are completely software controlled, 
therefore they can be written into your programmes. Hera are a few examples: A full set of space 
invaders — Pucfcman - Bulits, Bombs — Tanks - Laser Bases and Alien Ships. 

NO EXTRA POWER NEEDED 

KAYDE 16K GRAPHICS BOARD SOFTWARE 

■nan: The only true ZX version of the popular arcade game. 
Cen- In all I think this is me best presented moving graphic program I've yet seen" Phil Garratt, 

Interface. 

Space invaders; The best version available anywhere, 
Graphic Software can onlv be used with a Graohjcs board. 

KAYDE 16K 81 SOFTWARE 




apade 
face. 



'In all I think this is the best presi i ve yet seen" Phil Garrati 




3D.' 3D Labyrinth. A Cubit Maze that has corridors which may go left, right, up. down. 
Packmen Uhe latest addition in 81 ga^ 

WHY WAtT TO PA Y MORE 
FAST IMMEDIA TE DEL/VERY 

Post to: 

Dept SU 

Kayde Electronic Systems L td 

The Conge 

Great Yarmouth 

Norfolk NR3Q JPJ 

Tel; 0493 57867 (Dept SU) 

Don't Forget you can always order 
on the telephone with your credit card 

All products include VAT are futiy 
buiit and tested and come with a 
COMPLETE MONEY BACK GUARANTEE 





I enclose C 
Name 

Address 



Ptease add Ct. 50 P/P for aif hardware and 50p for eft software. 
Pfdime make cheques payable to Kayde Electronic Systems L td.